潘晶
, 黄翠华
Pan Jing, Huang Cuihua
中图分类号: P935.1;Q494
文献标识码: A
文章编号: 1001-8166(2018)04-0361-12
收稿日期: 2017-10-30
修回日期: 2018-02-5
网络出版日期: 2018-04-20
版权声明: 2018 地球科学进展 编辑部
基金资助:
作者简介:
First author:Pan Jing (1988-), female, Minqin County, Gansu Province, Ph. D student. Research areas include degraded land improvement.E-mail:panjing@lzb.ac.cn
作者简介:潘晶(1988-),女,甘肃民勤人,博士研究生,主要从事退化土地改良研究.E-mail:panjing@lzb.ac.cn
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摘要
土壤盐渍化是在特定的自然和人类活动共同作用下产生的全球性土壤退化问题。丛枝菌根真菌(AMF)作为一种有益土壤微生物,在盐渍土壤中数量繁多、种类丰富,且能够与植物根系形成互惠共生体——丛枝菌根,从而提高植物耐盐性,进而改良盐渍土。在分析盐胁迫对植物影响机制的基础上,总结了AMF提高植物耐盐性的相关机制:①通过重建植物体内离子平衡,缓解盐离子毒害和改善植物体内营养平衡;②通过扩大植物根系吸收范围和提高渗透调节能力,缓解植物体内水分亏缺;③通过激活植物抗氧保护体系,抵抗氧化胁迫对植物造成的损伤,从而保护植物细胞膜系统和光合系统的完整性,提高植物耐盐性。最后,提出了AMF改善土壤盐渍化研究的不足与亟需解决的科学问题,以期为我国西北干旱区盐渍土的改良和土地生产力的提高提供理论指导,服务于国家建设“西部生态屏障”和“丝绸之路经济带”战略目标的实施。
关键词：
Abstract
Soil salinization is one of the global land degradation problems due to the impacts of climatic variations and human activities. As a beneficial soil microorganism, Arbuscular Mycorrhizal Fungi (AMF) are abundant in saline-alkaline land and form a mutual symbiosis with plants, which can improve salt tolerance of plant and reduce salt stress from the soil. Based on the mechanism of salt stress on the plant, the effects of AMF on plant physiological characteristics were introduced. Three main aspects of the AMF effects were summarized as follows: reconstructing the ion balance in plants to alleviate the toxic effects of specific ions; expanding the absorption range of plant roots and improving the osmotic regulation ability to alleviate the water deficit in plant; maintaining the integrity of cell membrane system and photosynthetic system to resist the damage caused by oxidative stress. Also, the future research direction in this field was evaluated, then a reference for the reconstruction of the saline-alkaline environment was provided.
Keywords：
作为土地退化的主要表现形式之一,盐渍化已经成为一个全球性的环境问题。据统计,全球盐渍化土地的面积为9.54×108 hm2左右,约占世界陆地总面积的7%[1]。受全球变暖、区域性气候变化与人类活动的交互影响[2],盐渍化土地面积仍以每年10%的速度增加。按照该速度,至2050年全球约有50%的可耕地将变为盐渍化土地[3,4],直接影响全球粮食安全,严重制约社会经济的可持续发展。我国现有盐渍化土地约为3.63 ×107 hm2,占全国可利用土地面积的4.88%,且其中80%的盐渍化土地处于荒芜状态[4,5]。随着人口、土地、粮食矛盾的加剧,如何开发利用盐渍化土地对于促进我国经济发展、保障粮食安全、缓解人口压力和维持生态平衡都具有重大战略意义[6]。
德国植物生理学家Frank于1885年发现了真菌组织(菌丝)与植物根系的共生结合现象,并首次将土壤真菌与植物根系形成的共生体描述为菌根(Mycorrhizas)[7]。丛枝菌根真菌(Arbuscular Mycorrhizal Fungi, AMF)是陆地生态环境中的一种有益真菌,它可以与80%的陆生植物根系建立共生关系,并形成互惠共生体——丛枝菌根[3]。在盐渍土壤中,AMF也广泛分布,并且通过侵染植物根系形成丛枝菌根来影响植物生理、生化过程,从而缓解盐胁迫对植物的不利影响,提高植物耐盐能力,减轻盐害对植物生物量造成的损失[8,9]。
鉴于以上特征,通过对植物接种AMF提高植物耐盐性进而改良盐渍土成为该领域研究的前沿和热点。近年来,国内外众多学者对盐胁迫下植物接种AMF后植物生理、生化、生态特征的变化进行了广泛的实验研究,并取得了大量成果。这些研究可为利用AMF促进植物生长及改善生态环境的实践提供重要指导,但迄今为止,并没有得到系统的总结,在很大程度上阻碍了利用AMF改良盐渍土的实践。因此,本文系统总结了盐胁迫对植物的影响及AMF提高植物耐盐性的主要机制,旨在为我国西北内陆干旱区生态环境的恢复及盐渍土的改良提供理论支撑。
盐胁迫是自然界中主要的非生物胁迫之一,主要通过离子胁迫、渗透胁迫及氧化胁迫等次级反应过程来实现其对植物的破坏作用。
Na+和Cl-是盐渍土壤中对植物产生毒害的主要盐离子[10]。盐胁迫下,植物对离子吸收的选择性下降,大量Na+和Cl-进入植物细胞后,使细胞质内Na+和Cl-浓度过高,K+,Ca2+和Mg2+的吸收受到抑制,破坏了植物体内原有的离子平衡,导致植物遭受离子胁迫[10]。由于盐离子与其他营养离子间存在竞争关系,盐离子的过量积累一方面对植物产生离子毒害,另一方面会抑制植物对其他营养离子的吸收,如K+和Ca2+等,从而导致植物体内营养亏缺[3]。因此,离子胁迫使植物往往受到盐离子毒害和营养离子亏缺的双重伤害[11],干扰植物的正常代谢活动。
土壤盐渍化降低了植物根际土壤水的能量状态,使土壤溶液渗透压超过了植物细胞液的正常渗透压,导致植物遭受渗透胁迫[10,12]。植物根系感受到胁迫信号之后,其内源激素通过3个途径迅速做出响应:①主根生长素(Auxin,IAA)的运输途径被扰乱,导致主根伸长区的生长受到抑制[13];②根部乙烯(Ethylene,ETH)信号途径被激活,产生的高浓度乙烯抑制侧根的萌发[13];③植物根部脱落酸(Abscisic Acid,ABA)的合成抑制侧根的伸长[14]。这3个途径的交叉作用使植物主根生长和侧根萌发与伸长都受到抑制。同时,植物根系转录因子也做出响应,特别是转录因子GL2被激活后致使根毛密度下降[13]。此外,盐胁迫下,根系的凯氏带长度和木栓质数量增加,阻碍水分运输,导致根系水导度降低[13]。因此,渗透胁迫导致植物根系长度、密度和结构的改变,阻碍植物对土壤水分和养分的摄取,导致植物处于生理干旱状态,生育速度开始变得缓慢,甚至萎蔫或死亡。
土壤盐渍化除了使植物遭受渗透胁迫和离子胁迫,还通过二者的相互作用产生次级的氧化胁迫[15],致使植物体内活性氧产生与清除间的动态平衡被破坏。当活性氧的积累量超过了其伤害阈值,就会在2个方面对植物产生氧化损伤[16]:一方面造成膜脂过氧化加剧和脱脂作用,使植物细胞膜系统的完整性遭到破坏[13];另一方面造成植物体内负责光合色素合成的特异性酶活性下降[17],叶绿体基粒片层膨胀松散乃至片层解体,光合系统中的超微结构遭到破坏[18],影响植物进行光合作用[19]。
综上所述,在离子胁迫、渗透胁迫和氧化胁迫的多重作用下,植物一系列生理生化代谢紊乱,植物正常生理代谢活动受阻(图1)。
盐胁迫会对植物造成伤害,导致植物一系列生理生化代谢紊乱,生长受阻甚至死亡。植物若要在盐渍土壤中正常生长,必须要具备抵抗离子胁迫、渗透胁迫和氧化胁迫的能力。AMF通过建立植物体内新的离子平衡、缓解植物体内水分亏缺和增加植物抗氧化能力等机制,提高植物耐盐性,缓解盐胁迫对植物造成的伤害。
植物耐盐机理的实质是盐离子与其他离子代谢的关系问题[20]。重建植物体内新的离子平衡机制,是提高植物耐盐性的重要途径[21]。AMF可以促进与调节植物对营养离子的吸收,控制盐离子在植物体内的运输和转移,以此帮助宿主植物建立新的离子平衡[22,23]。
3.1.1 促进与调节对营养离子的吸收
促进盐胁迫下植物对营养离子的吸收是提高植物耐盐性的关键。AMF通过菌丝强大的吸收和运输能力、植物根系吸收范围的扩大[24]和菌根分泌物对土壤矿质营养元素的活化(特别是磷)等机制[25],促进宿主植物对其生长所必需元素的吸收。土壤中磷(P)、锌(Zn)和铜(Cu)等营养离子不易移动,很难被植物吸收利用。AMF侵染植物后,在植物根系会产生大量根外菌丝。菌丝数量多于植物根毛、菌丝体寿命长于根毛且菌丝可以扩展到比根系更远的土壤中[25]。菌丝的存在实现了土壤营养离子到植物根系的快速转移和运输。植物体内80%以上的P,50%以上的Zn和Cu来自于根外菌丝的直接吸收[26]。盐胁迫下,接种Glomus mosseae的黄瓜体内P,Cu和Zn含量分别比对照提高11.7%,13.5%和9.9%[27];接种Glomus mosseae的番茄幼苗地上部分的P,Cu和Zn含量也显著高于对照,说明AMF能够显著促进植物对土壤中P,Zn和Cu的吸收[28]。植物接种AMF后,体内N,K,Ca,Mg,Fe和Mn等含量也会提高。在0.15% NaCl胁迫下, 接种Glomus mosseae的紫薇叶片中N含量是对照的1.5倍[24]。在4.3 mS/cm NaCl胁迫下,与对照相比,接种Glomus mosseae的芦笋幼苗地上部分K+,Ca2+和Mg2+含量分别增加了58.4%,50.4%和76.0%,根系K+,Ca2+和Mg2+含量分别增加了76.9%,23.1%和22.5%[29];在50,100和200 mmol/L NaCl胁迫下,接种Glomus intraradices的葫芦巴体内Fe3+和Mn2+显著高于对照[30]。
此外,AMF能够调节和平衡植物体内营养吸收。K+/Na+和Ca2+/Na+可以反映盐胁迫下植物的耐盐性[31]。土壤中盐浓度较高时,高盐促进植物对Na+的吸收,阻止植物对K+和Ca2+的吸收和运输,从而降低了植物体内的K+/Na+和Ca2+/Na+,破坏了细胞质内的离子平衡和多种代谢途径。植物接种AMF后,体内K+和Ca2+比例的增加可以降低Na+和Cl-的相对含量,并保持较高的K+/Na+和Ca2+/N
3.1.2 控制盐离子的吸收和运输
盐胁迫下对植物产生毒害的盐离子主要是Na+和Cl-[10]。防止Na+进入根部、控制Na+向地上部分运输和分配以及Na+在液泡中的固存是植物应对高盐环境的主要策略[34]。AMF可以降低宿主植物根部对盐离子的吸收,控制盐离子向地上部分运输,减轻盐离子对植物造成的伤害。一方面,菌根共生体可以将Na+保存在根外菌丝中,土壤中的Na+尚未进入植物根系就将其排除,从而控制Na+向地上部分的运输。例如,在高盐胁迫下,接种Glomus intraradices 和Glomus mosseae的沙枣根部Na+含量较对照分别降低了17.39%和9.5%,叶片Na+含量较对照分别降低了19.19%和9.03%[35]。葫芦巴[30]和胡椒[36]接种AMF后,植株体内Na+含量也显著降低。另一方面,AMF引起植物根细胞数量增多,菌根植物可以将Na+分隔在根细胞液泡中,从而使细胞区隔化的Na+和Cl-增多,减少了盐离子向地上部分的运输[37]。例如,洋葱[38]和盐地碱蓬[37]接种AMF后,地上部分Na+和Cl-含量降低,根部Na+和Cl-含量明显增高。研究表明,高盐胁迫下生长的植物主要利用质膜和液泡膜上的Na+/H+逆向转运蛋白,将Na+排出胞外或区隔化在液泡中,以此来消除Na+对植物细胞的毒害[19]。植物Na+/H+逆向转运蛋白的过量表达可以显著提高植物耐盐性[39]。目前,关于接种AMF后植物Na+/H+逆向转运蛋白的研究相对较少,且已有结果表明接种AMF并未促进植物Na+/H+逆向转运蛋白的过量表达[39,40](表1)。因此,关于盐胁迫下Na+/H+逆向转运蛋白参与离子平衡的方式和机制有待进一步研究。
另有研究表明,AMF对植物盐离子吸收的影响与植物品种、植物部位、盐胁迫强度和实验所处阶段等多种因素密切相关。Asghari[41]研究表明,在试验初期,高盐和低盐处理下,接种AMF的三叶草地上部分Na+含量上升,根部Na+含量下降;试验后期,低盐处理下接种AMF的三叶草Na+含量升高,高盐处理下接种AMF后Na+含量下降。郭江源等[42]的研究结果表明,在盐碱化湿地上,芦苇接种AMF后,其地上部分和根部Na+和Cl-的含量均没有产生显著性的影响。
表1 AMF对植物Na+/H+ 逆向转运蛋白基因影响的部分实验结果
Table 1 Some experimental results of AMF effects on plant Na+/H+ antiporter genes
| 供试植物 | 真菌类型 | 接种效应 | 参考文献 |
|---|---|---|---|
番茄 | Glomus geosporum+ Glomus intraradices | Le NHX1 ○ Le NHX2 ○ | [40] |
| Glomus mosseae | Le NHX1 ↓ | [39] |
如前文所述,盐胁迫通过渗透胁迫导致植物体内水分亏缺,抑制植物生长[16]。而植物接种AMF后,通过根外菌丝对水分吸收和运输的直接作用机制及通过植物根系形态的改善、不同植物激素间的协同和植物渗透调节能力的提高等间接作用机制,改善植物体内水分吸收与代谢,间接增强植物的耐盐能力。此外,盐胁迫下菌根植物体内水分含量增加,有效地稀释盐离子浓度,也相应地减轻了盐离子对植物的伤害[32]。
3.2.1 根外菌丝对水分吸收和运输
水分的进出直接影响植物细胞的渗透势[43]。菌丝可以调节植物对水分的吸收和运输,增强植物对盐碱胁迫的适应能力,是AMF缓解植物缺水况状的直接作用机制。菌丝的半径(约0.005 mm)小于根和根毛半径(约0.15 mm)[44],可以穿过植物根和根毛不能穿过的土壤孔隙,延伸到距离根12 cm以外且根毛触及不到的土壤中吸收营养和水分[26]。同时,菌丝的隔膜稀少或无隔膜,其内部的水分运输几乎没有阻力,水分可直接通过菌丝迅速到达根系顶端丛枝,进而渗入到植物根内细胞,从而提高宿主植物的水分吸收和运输能力[45]。研究表明,大麦接种Glomus intraradices后,菌丝对总水分吸收量的贡献率约占20%[46]。可见,菌丝自身特性的发挥可使植物根系对水分的吸收范围增大、运输能力增强[47,48]。
3.2.2 根系形态和生理特征的改善,提高水分吸收与代谢
根系部分是植物遭受盐胁迫的首要部位[13]。盐胁迫下植物根系会对土壤状况进行“测量”,启动ABA合成系统产生大量ABA,同时根系中IAA、赤霉素(Gibberellin,GA)和细胞分裂素(Cytokinin,CTK)含量减少,导致植物根系形态和生理特征发生变化,直接影响植物的正常生长[13,4951]。已有研究结果表明:当植物接种AMF后,菌丝可以通过释放激素或诱导宿主植物产生内源激素[51],影响植物根系形态发生变化,显著降低植物根尖坏死率,以此来促进植物对水分的吸收[52]。同时,AMF侵染植物形成菌根后,能够改善植物营养水平,进而促进根系生长、扩大根系吸收范围和能力,从而相应提高植物根系对水分的吸收和利用[25]。通过对文献整合分析(Meta-analysis)[24],得到AMF对植物根系形态各指标的权重响应比(图2)。由图2可见:盐胁迫下,AMF侵染植物后能诱导植物根系长度、直径和根尖数显著增加,促使根系表面积和体积显著扩大。菌根植物根系形态的改善使植物根系对水分的吸收范围和吸收能力相应提高[53]。盐胁迫下,AMF不仅通过释放和诱导植物激素来改善植物对水分的吸收,而且通过加强不同激素间的协同作用来影响植物的水分代谢。贺忠群等[51]研究发现,CTK与ABA之间存在极显著的负相关,两者共同调节气孔开放,有利于盐胁迫下植物的水分代谢和光合作用。
图2 AMF对植物根系形态各指标的权重响应比
空心圆圈代表响应比,误差线代表95%的置信区间;误差线没有跨越零线表示处理与对照存在显著差异;若响应比为正,则说明盐胁迫下AMF可促进植物根系生长;反之亦然
Fig.2 Weighted response ratio of salinity and mycorrhizal associations on root morphology of plant
Open circles denote the overall mean response ratio; Error bars denote 95% CI. The 95% CI that do not go across the zero line mean significant difference between treatment and control. Positive values indicate an increase in root morphology parameter; Negative values indicate that the treatment is deleterious to root growth
3.2.3 渗透调节能力的提高,促进水分运输
渗透调节能力是植物耐盐的最基本特征[54]。植物渗透调节过程包括增加溶质和增加透水[43]。盐胁迫下菌根植物通过合成渗透调节物质和增加细胞透水性,来缓解渗透胁迫给植物造成的伤害,保障植物生长所需水分,增强植物耐盐性。具体机制如下:
(1) 合成渗透调节物质
盐胁迫下,植物主要通过合成无毒有机溶质来降低细胞液的渗透势,从而促进水分向植物体的运输[45],如甜菜碱的积累对于平衡细胞质和液泡之间的水势有重要作用[55];可溶性糖直接参与其他化合物的合成、维持细胞膜的稳定[56]。可溶性蛋白具有较强的亲水性[56]。在相同的盐浓度下,接种AMF的植物体内甜菜碱[57,58]、可溶性糖[59]和可溶性蛋白[33,60]含量均显著高于未接种植物。Al-Garni[57]研究发现,高盐胁迫下接种AMF的芦苇体内甜菜碱含量比对照高2倍左右。韩冰等[61]研究表明,与对照相比,盐胁迫条件下接种AMF的黄瓜叶片内可溶性糖和可溶性蛋白含量分别增加8.0%和10.2%,根系可溶性糖和可溶性蛋白含量分别增加7.9%和7.1%。
脯氨酸是衡量植物渗透调节能力的重要指标之一[16]。然而,关于盐胁迫下接种AMF对植物体内脯氨酸含量的影响,不同研究者的观点并不一致。一些学者认为脯氨酸是一种渗透保护剂,脯氨酸积累是盐胁迫下植物的一种保护性措施[62],其含量大小表示植物抗逆性的强弱。盐胁迫下接种AMF后,小麦[33]、沙枣[35]、麻黄[63]等植物的叶片和根部脯氨酸含量普遍升高,认为AMF通过积累脯氨酸来提高植物耐盐性。另一些学者则认为植物体内脯氨酸含量的积累可能是植物在高盐胁迫下的一种胁迫症状。盐胁迫下脯氨酸含量的大小可以反映植物遭受盐害的程度,如果植物体内脯氨酸含量下降,则说明植物受到的盐胁迫伤害程度较轻,植物抗逆性较强[64,65]。盐胁迫下生菜[47]和高羊茅[32]接种AMF后,叶片脯氨酸含量显著低于对照,认为这是由于菌根植物受到盐胁迫伤害程度较轻导致脯氨酸积累量较低。也有学者认为脯氨酸在总有机溶质中的相对丰度较低,脯氨酸对菌根植物的渗透平衡和耐盐性几乎没有影响[66]。因此,关于脯氨酸在植物抗逆性中的作用及盐胁迫下接种AMF后脯氨酸含量升高或降低的机制值得系统探索。
盐胁迫下菌根植物体内渗透调节物质的参与,使细胞保持较低的渗透势,从而缓解渗透胁迫造成的水分亏缺对植物的伤害。
(2)增加细胞透水性
水孔蛋白(Aquaporins,AQPS)是一种能使水分子沿着水势差进行跨膜运输且不需要生物提供直接能量的通道蛋白[67]。AQPS对植物根系水分运输具有重要作用。流经植物根部的水中,有70%90%是通过AQPS来增加渗透势或水力学导度来传输的[68]。根系水力学导度的改善对水分运输具有促进作用。盐胁迫下对植物接种AMF后,植物体内ABA和GA等植物内源激素含量发生变化,可促进植物根细胞膜上AQPS的基因表达[12]。菌根植物通过AQPS基因的上调或下调参与渗透调节,加快了植物体内水分的运输和传递,缓解由盐分导致的渗透胁迫对植物造成的伤害[40,6971]。但是由于不同基因各自调控表达模式不同,对盐胁迫及AMF的响应程度不同,因此,不同研究者所获得的结果也不一致。目前,关于盐胁迫下AQPS基因参与渗透调节的方式和机制尚不清楚,有待进一步研究(表2)。
表2 AMF对植物AQPS影响的部分实验结果
Table 2 Some experimental results of AMF effects on plant AQPS
| 供试植物 | 真菌类型 | 接种效应 | 植物水分状态 | 参考文献 | |
|---|---|---|---|---|---|
| 番茄 | Glomus geosporum +Glomus intraradices | Le PIP1 Le PIP2 Le TIP | ↓ ○ ↓ | [40] | |
| Glomus mosseae | Le AQP2 Le PIP1 Le PIP2 Le TRAMP Le TIP | ↑ ↓ ↓ ↓ ↓ | 相对含水量(RWC) ↑ 叶片水势(Ψw) ↑ 根系水导 (Lpr)升高 ↑ | [71] | |
| 菜豆 | Glomus intraradices | PvPIP1;1 PvPIP1;2 PvPIP1;3 PvPIP2;1 | ↑ ↓ ↑ ↑ | 相对水含量(RWC) ↑ 自由渗出流(Jv) ↑ 根系水导 (Lpr)升高 ↑ | [69] |
| 生菜 | Glomus intraradices | LsPIP1 LsPIP2 | ↑ ○ | 相对水含量(RWC) ↑ | [70] |
提高植物体内的抗氧化酶活性及抗氧化代谢水平是增强植物耐盐性的途径之一[16]。AMF可以激活植物抗氧保护体系,抵抗氧化胁迫对植物造成的损伤,从而保护植物细胞膜系统和光合系统,提高植物耐盐性。
3.3.1 激活抗氧保护体系,保护膜系统完整性
抗氧保护体系包括酶促保护系统和非酶促保护系统[34]。酶促保护系统由抗氧化酶组成,主要包括超氧化物歧化酶(Superoxide Dismutase,SOD)、过氧化物酶(Peroxidase,POD)、过氧化氢酶(Catalase,CAT)、抗坏血酸过氧化物酶(Ascorbate Peroxidase,APOX)和谷胱甘肽还原酶(Glutathione Reductase,GR)等。保持抗氧化酶活性之间的平衡,可以减少活性氧对植物的损伤。在75 mmol/L NaCl胁迫下,接种球囊霉属混合菌剂的麻黄体内SOD,POD,CAT,APX和GR活性与对照相比,分别增加了26.53%,20.90%,33.55%,20.15%和25.00%[63]。在100 mmol/L浓度的盐胁迫下,接种Glomus mosseae的番茄叶片内SOD,CAT和POD活性与对照相比,分别提高了56%,37%和28%[72]。可见,AMF可以显著激活盐胁迫下宿主植物体内抗氧化酶活性。非酶促保护系统中,目前研究最多的是抗坏血酸(Ascorbic Acid,AsA)。AMF可显著提高宿主植物AsA含量。以Glomus mosseae作为供试菌种时,在100 mmol/L浓度的盐胁迫下接种AMF的番茄叶片内AsA比对照高33%[72];在0.8%,1.2%和1.6%盐胁迫下,接种AMF的高羊茅草体内AsA含量分别比对照提高了9.1%,12.4%和19.5%[32]。
植物体内抗氧化代谢水平的提高导致活性氧含量降低。盐胁迫下对玉米接种Glomus mosseae后,叶片中H2O2含量在0.5 g/kg盐浓度下显著低于对照,
AMF可激活抗氧保护体系,减少活性氧对植物造成的氧化损伤,保护细胞膜系统结构和功能的稳定性[74]。丙二醛(Malondiadehyde,MDA)作为脂质过氧化的最终分解产物,其含量的变化是衡量膜损伤程度的标志之一[16]。接种AMF后植物体内细胞膜透性和MDA含量低于对照。在1.2% NaCl胁迫下,与对照相比,接种Glomus mosseae的高羊茅叶片膜透性和MDA分别降低了25.6%和35.4%[32]。在3‰ NaCl胁迫下,与对照相比,接种Glomus mosseae的红花叶片中MDA含量降低了22.3%[74]。可见,AMF能显著降低盐胁迫对细胞膜系统造成的损伤,缓解盐胁迫对植物造成的不利影响。
3.3.2 保护光合系统功能的发挥
植物体内活性氧过量也会对光合器官造成损伤[75]。接种AMF后,菌根植物体内P[18] 和Mg[74]的吸收显著增加,缓解了叶绿素的分解代谢。叶绿体和线粒体中抗氧化酶活性的提高保护了光合系统结构的完整性,促进了盐胁迫下植物的光合作用[75]。
叶绿体中的叶绿素含量直接影响着植物进行光合作用。盐胁迫下对植物接种AMF可以提高植物叶绿素含量[62,76]。徐瑶等[74]在1‰,2‰和3‰ 3种不同NaCl浓度下对红花接种Glomus mosseae后发现,接种AMF的植物体内叶绿素含量显著高于对照,特别是在2‰和3‰盐浓度下,叶绿素含量分别增加了104.0%和111.9%。
净光合速率(Pn)能有效反映植物耐盐能力。盐胁迫对植物叶片Pn具有明显抑制作用。光合速率下降因素分为气孔因素和非气孔因素,受气孔因素影响时,气孔导度(Gs)和胞间CO2浓度(Ci)降低;受非气孔因素影响时,Ci含量升高[77]。盐胁迫下接种AMF后,植物叶片的Gs和Pn显著高于对照[18,47],说明接种AMF后叶片气体交换能力提高,植物光合特性改善。盐胁迫下接种AMF后,植物叶片Ci含量变化不一致。Sheng等[78] 的研究表明,盐胁迫导致玉米叶片Pn 降低、Ci升高,但接种AMF后玉米叶片Pn显著高于未接种植物,而Ci显著低于未接种植物,说明玉米光合作用主要受气孔限制影响;与之相反,孙玉芳等[35]的研究结果则显示盐胁迫下对沙枣接种AMF后,叶片Ci升高,沙枣光合作用受非气孔限制影响有关。
叶绿素荧光被视为反映植物光合作用与环境关系的内在探针,具有快速和对植物无损伤等优点,其变化能够反映光合作用过程中光系统对光能的吸收、传递、分配、耗散和转换的能力[19,79,80]。因此,叶绿素荧光各个参数的变化可以作为反映植物盐胁迫程度的指标。叶绿素荧光各参数值降低,说明盐胁迫使光系统II(PSII)受到损伤,植物受盐胁迫的影响较大。可变光(Fv)和最大荧光(Fm)间的比率(Fv/Fm)可以反映植物的光合速率。非化学淬灭系数(NPQ)反映了PSII天线色素所吸收的光能中用于热耗散的比例,高的NPQ有利于过剩光能的及时耗散,从而避免光系统的损害[77]。盐胁迫下菌根植物叶片中Fv/Fm,NPQ等均显著高于非菌根植物[78,81],进一步说明AMF可以提高植物光合速率,避免光系统受损,从而提高植物的耐盐性。
基于盐胁迫下植物的受损机制,我们认为AMF提高植物耐盐性的主要机制包括以下3点:①通过重建植物体内离子平衡,缓解盐离子毒害和改善植物体内营养平衡;②通过扩大植物根系吸收范围和提高渗透调节能力,缓解植物体内水分亏缺;③通过激活植物抗氧保护体系,抵抗氧化胁迫对植物造成的损伤,从而保护植物细胞膜系统和光合系统的完整性,提高植物耐盐性(图3)。
图3 AMF提高植物耐盐性的机制
Fig.3 The mechanism of Arbuscular Mycorrhizal Fungi enhancing salt tolerance of plants
但目前有些机制尚不清楚或仍存在争议。为进一步探明AMF在提高植物耐盐性和改良盐渍土中的作用,建议今后对以下方面做进一步研究,将有助于更加深入地了解相关机理和过程:
(1)目前研究的植物多集中于非盐生植物,对于盐生植物的研究则极其少见。盐生植物能够在盐渍土壤中正常生长并形成自然盐生植物植被,为干旱区内陆河流域生态系统的稳定提供保障。近年来,内陆河流域下游不当取水灌溉致使土壤中滞留的盐分不断增加,导致该区域自然生长的盐生植物大量死亡,生态环境变得更为脆弱。如果能通过对盐生植物接种AMF提高其在高盐环境下的生存和生长,对于改善和修复内陆河流域乃至中亚地区的盐渍化土地都具有重要的生态学意义和应用价值。然而,AMF提高植物耐盐性的3个主要机制是否适用于盐生植物还是未知,这阻碍着大面积推广利用AMF和盐生植物来改善盐碱地。今后可加强AMF与盐生植物的研究,为西北盐渍化土地改良和生态环境治理提供理论依据。
(2)不同AMF对不同盐分类型、不同胁迫强度和不同胁迫时间的耐受能力不同,对不同植物及同一植物不同部位的影响也不同。由于这种差异的存在,用一个标准来界定AMF对植物的促生效果是不确切的。今后应针对不同盐渍土壤类型、不同植物种类和不同部位,确定各自适当的评价标准,以便于更好地认识AMF对植物和土壤的影响,为筛选高效耐盐的AMF菌种及其应用提供理论和技术依据。
(3)关于AMF提高植物耐盐性的研究目前多集中于生理生化水平,而在分子水平上的研究则相对较少,仅限于对少数几个基因(如Na+/H+ 逆向转运蛋白基因、AQPS的基因和△1-吡咯啉-5-羧酸合成酶基因等)的部分了解。今后应进一步深入了解分子水平上相关基因表达在菌根应用中的作用,以便更全面地揭示AMF提高植物耐盐性的相关机制。
(4)菌根学研究已经从个体水平向群落和生态系统方向发展,AMF不仅对单个植物产生影响,而且对整个植物群落及其多样性和稳定性产生作用。但目前盐胁迫下菌根对植物促生作用的研究,更多的还是局限在温室环境和人工模拟条件下对单种植物进行盆栽试验研究,而对在自然盐渍生境下植物间的营养分配和水分传递等方面的研究尚属空白。今后可以围绕自然盐渍生境下植物间或群落水平下丛枝菌根网络(Arbuscular Mycorrhizal Network)进行研究,并探索AMF对群落的发生、演替和结构等方面的影响,以便对AMF改良盐渍土有更深层次的认识。
(5)AMF是土壤和植物的重要组成部分,连接着植物根系与土壤,它不仅有利于盐胁迫下植物生长,而且还能改良植物根区土壤环境。但目前关于盐胁迫下AMF的研究大多集中在其对宿主植物的促生效应,而对AMF及其与菌根际其他微生物的协同作用对盐渍土影响的相关研究则鲜有涉及。今后可加强AMF与菌根际其他微生物的协同作用改良盐渍土的相关研究,为更好地揭示AMF在盐渍土改良中的生态学功能提供理论依据。
The authors have declared that no competing interests exist.
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The present situation and hot issues in the salt-affected soil research [J].土壤盐渍化研究现状及未来研究热点 [J].
随着全球气候暖化问题的日益加剧，土壤盐渍化问题已经成为各国关心的全球性问题，全球约有7％的土地受到盐渍化的威胁，而且这个数字还在上升。我国是土壤盐渍化比较严重的国家，盐渍化土壤面积大，分布广，对区域农业发展构成了严重的威胁。本文对70年来我国土壤盐渍化研究的内容框架进行了梳理和概括，并结合国内外的相关研究成果对已有研究中存在的不足进行了评述；借助文献数据库和相关数据共享网络对近30年来国内外盐渍土研究的趋势和总体概况进行了总结，提出了新形势下土壤盐渍化研究的5个重点领域和方向，旨在为今后开展盐渍土研究提供新的思路。
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| [5] |
Progress in techniques of improvement and utilization of saline-alkali land in China and its future trend [J].中国盐碱地改良利用技术研究进展及未来趋势 [J].
土壤盐碱化已成为世界性的难题。我国盐碱地面积大、分布广，且耕地盐碱化问题日益严重。在人口不断增加，耕地不断退化的情况下，合理改良利用盐碱地对于我国粮食和能源安全具有重大意义。本文结合多年科研工作介绍了目前用于盐碱地改良利用的技术方法，包括水利方法、物理方法、化学方法和生物学方法，分析了其效果及优缺点，重点阐述了生物学方法是改良盐碱地最经济、最有效并可持续的方法。在今后改良利用盐碱地的实践中，应因地制宜，灵活采取水利工程方法、物理方法、化学方法和生物学方法相结合的综合治理方案。Soil salinization has become a worldwide problem. Saline-alkali landofChinais characterized by extensive distribution and large area. Moreover, the degree of soil salinization is becoming more serious in cultivated land. As the population of China increases and cultivated land is degraded, to improve and utilize saline-alkali land reasonably is of great significance and importance. This paper summarizes the application, effect and the advantage and disadvantage of techniques in improving saline-alkali land, including water conservancy measures, physical measures, chemical measures and biological measures. Biological measure is discussed in detail and considered as the most economical and effective way to improve saline-alkali land. In the future, comprehensive strategy which integrates water conservancy measures, physical measures, chemical measures and biological measures, and adjusts these measures to local conditions should be used to improve and utilize saline-alkali land.
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| [6] |
Coastal reclamation and saltmarsh carbon budget: Advances and prospects [J].滩涂围垦对盐沼湿地碳收支的影响研究进展 [J]. |
| [7] |
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| [8] |
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| [9] |
Arbuscular mycorrhizal fungi and plant symbiosis in a saline-sodic soil [J].
The seasonality of arbuscular mycorrhizal (AM) fungi鈥損lant symbiosis in Lotus glaber Mill. and Stenotaphrum secundatum (Walt.) O.K. and the association with phosphorus (P) plant nutrition were studied in a saline-sodic soil at the four seasons during a year. Plant roots of both species were densely colonized by AM fungi (90 and 73%, respectively in L. glaber and S. secundatum ) at high values of soil pH (9.2) and exchangeable sodium percentage (65%). The percentage of colonized root length differed between species and showed seasonality. The morphology of root colonization had a similar pattern in both species. The arbuscular colonization fraction increased at the beginning of the growing season and was positively associated with increased P concentration in both shoot and root tissue. The vesicular colonization fraction was high in summer when plants suffer from stress imposed by high temperatures and drought periods, and negatively associated with P in plant tissue. Spore and hyphal densities in soil were not associated with AM root colonization and did not show seasonality. Our results suggest that AM fungi can survive and colonize L. glaber and S. secundatum roots adapted to extreme saline-sodic soil condition. The symbiosis responds to seasonality and P uptake by the host altering the morphology of root colonization.
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| [10] |
Advances in plant cell ion flux with salt stress:A review [J].盐胁迫下植物细胞离子流变化的研究进展 [J].
<p>土壤盐化是全球面临的最严峻的环境问题之一，盐离子在细胞内大量积累会对植物造成毒害。在盐胁迫下，钠离子（Na<sup>+</sup>）通过非选择性阳离子通道进入胞内并引起质膜去极化，进而激活外向钾离子（K<sup>+</sup>）通道使钾离子外流。在耐盐植物中，钾离子外流可被明显抑制，从而维持胞内较高的K<sup>+</sup>/Na<sup>+</sup>以降低盐胁迫伤害。植物细胞质膜上的H<sup>+</sup>-ATP酶可将氢离子（H<sup>+</sup>）泵到胞外，从而形成质子动力势以驱动Na+/H+反向运输体将胞内钠离子排出。钙离子（Ca<sup>2+</sup>）在盐胁迫条件下会流向胞内，使胞内钙离子浓度升高，进而调控钠离子和钾离子的跨膜流动。氯离子（Cl<sup>－</sup>）在盐胁迫下会流向胞外，这种流动可能与钠离子外流相偶联。主要就这几种离子在盐胁迫下的跨膜流动及其调控机制进行综述，以期对离子流的深入研究有所帮助。图2参60</p>
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| [11] |
Microbial amelioration of crop salinity stress [J].
Abstract The use of soil and irrigation water with a high content of soluble salts is a major limiting factor for crop productivity in the semi-arid areas of the world. While important physiological insights about the mechanisms of salt tolerance in plants have been gained, the transfer of such knowledge into crop improvement has been limited. The identification and exploitation of soil microorganisms (especially rhizosphere bacteria and mycorrhizal fungi) that interact with plants by alleviating stress opens new alternatives for a pyramiding strategy against salinity, as well as new approaches to discover new mechanisms involved in stress tolerance. Although these mechanisms are not always well understood, beneficial physiological effects include improved nutrient and water uptake, growth promotion, and alteration of plant hormonal status and metabolism. This review aims to evaluate the beneficial effects of soil biota on the plant response to saline stress, with special reference to phytohormonal signalling mechanisms that interact with key physiological processes to improve plant tolerance to the osmotic and toxic components of salinity. Improved plant nutrition is a quite general beneficial effect and may contribute to the maintenance of homeostasis of toxic ions under saline stress. Furthermore, alteration of crop hormonal status to decrease evolution of the growth-retarding and senescence-inducing hormone ethylene (or its precursor 1-aminocyclopropane-1-carboxylic acid), or to maintain source-sink relations, photosynthesis, and biomass production and allocation (by altering indole-3-acetic acid and cytokinin biosynthesis) seem to be promising target processes for soil biota-improved crop salt tolerance.
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| [12] |
Arbuscular mycorrhizal fungi in alleviation of salt stress: A review [J].
61 Background Salt stress has become a major threat to plant growth and productivity. Arbuscular mycorrhizal fungi colonize plant root systems and modulate plant growth in various ways. 61 Scope This review addresses the significance of arbuscular mycorrhiza in alleviation of salt stress and their beneficial effects on plant growth and productivity. It also focuses on recent progress in unravelling biochemical, physiological and molecular mechanisms in mycorrhizal plants to alleviate salt stress. 61 Conclusions The role of arbuscular mycorrhizal fungi in alleviating salt stress is well documented. This paper reviews the mechanisms arbuscular mycorrhizal fungi employ to enhance the salt tolerance of host plants such as enhanced nutrient acquisition (P, N, Mg and Ca), maintenance of the K62:Na62 ratio, biochemical changes (accumulation of proline, betaines, polyamines, carbohydrates and antioxidants), physiological changes (photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation, nodulation and nitrogen fixation), molecular changes (the expression of genes: PIP, Na62/H62 antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. Theis review identifies certain lesser explored areas such as molecular and ultrastructural changes where further research is needed for better understanding of symbiosis with reference to salt stress for optimum usage of this technology in the field on a large scale. This review paper gives useful benchmark information for the development and prioritization of future research programmes.
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| [13] |
Progress of studies on salt tolerance mechanisms in plant root system under salt stress [J].植物根系耐盐机制的研究进展 [J].
植物根系能够摄取土壤环境中的养分与水分,在植物的生长发育中起重要的作用。植物根系由于直接与土壤环境相接触会受到非生物胁迫较大的影响。盐胁迫是主要的非生物胁迫之一,对植物根系会产生较大的伤害。综述根系在组织形态和细胞水平上对盐胁迫的应答,以及根系响应盐胁迫的信号传导途径、转录因子与基因,对植物根部耐盐机制的解析和植物耐盐基因工程工具基因的挖掘具有重要意义。
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| [14] |
Endodermal ABA signaling promotes lateral root quiescence during salt stress in Arabidopsis seedlings [J].
The endodermal tissue layer is found in the roots of vascular plants and functions as a semipermeable barrier, regulating the transport of solutes from the soil into the vascular stream. As a gateway for solutes, the endodermis may also serve as an important site for sensing and responding to useful or toxic substances in the environment. Here, we show that high salinity, an environmental stress widely impacting agricultural land, regulates growth of the seedling root system through a signaling network operating primarily in the endodermis. We report that salt stress induces an extended quiescent phase in postemergence lateral roots (LRs) whereby the rate of growth is suppressed for several days before recovery begins. Quiescence is correlated with sustained abscisic acid (ABA) response in LRs and is dependent upon genes necessary for ABA biosynthesis, signaling, and transcriptional regulation. We use a tissue-specific strategy to identify the key cell layers where ABA signaling acts to regulate growth. In the endodermis, misexpression of the ABA insensitive1-1 mutant protein, which dominantly inhibits ABA signaling, leads to a substantial recovery in LR growth under salt stress conditions. Gibberellic acid signaling, which antagonizes the ABA pathway, also acts primarily in the endodermis, and we define the crosstalk between these two hormones. Our results identify the endodermis as a gateway with an ABA-dependent guard, which prevents root growth into saline environments.
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| [15] |
Plant salt tolerance [J]. |
| [16] |
Research advance in the effects of salt stress on plant and the mechanism of plant resistance [J].盐分胁迫对植物的影响及植物耐盐机理研究进展 [J].
盐分是影响植物生长的一个重要环境因素。总结了盐分胁迫对植物生长发育影响的研究进展，从氧自由基产生、膜脂过氧化、离子伤害、渗透伤害和有毒物质积累等方面系统分析了盐胁迫对植物的伤害机理，并综述了植物对盐分胁迫的适应机制，总结了主要的抗盐生理指标。
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| [17] |
Studies on salt stress tolerance of citrus rootstock genotypes with arbuscular mycorrhizal fungi [J].
The effect of root colonization by Arbuscular Mycorrhizal fungi (AM fungi) on salt tolerance was studied in two citrus genotypes, Karna Khatta (Citrus Karna) and Troyer Citrange (Poncirus trifoliata x Citrus sinensis). Three-month-old seedlings were inoculated with the indigenous soil based AM inocula (mixed strains). The salinity gradient was developed by frequent irrigation with NaCl solutions (0, 50, 100, 150 mM w/v). Our results showed that all the physical variables studied were affected by the salinity. Proline accumulation increased, whereas chlorophyll, Ca and Mg concentrations decreased significantly with increasing salinity. In general, the decreased AM colonization did not show any significant effects under salt stress.
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| [18] |
Effect of phosphorus stress and AMF on photosynthesis in strawberry under salt stress [J].磷和丛枝菌根真菌对盐胁迫草莓光合作用的影响 [J].
用盆栽法研究了缺磷和接种丛枝菌根真菌对盐胁迫草莓(品种为‘达塞莱克特’)光合参数的影响。结果表明:在150 mmolL NaCl盐胁迫条件下,无论接种AM真菌与否,草莓植株均受到伤害,叶绿素含量降低,净光合速率(Pn)下降,但接种丛枝菌根真菌和磷处理的植株叶绿素含量、净光合速率、气孔导度(Gs)、气孔限制值(Ls)和胞间CO2浓度(Ci)均高于缺磷处理,盐害指数低。
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| [19] |
Mechanisms of salinity tolerance [J]. |
| [20] |
Screening of Saline/Alkaline-tolerant Ectomycorrhizal Fungi Strains and the Study of Ectomycorrhizal Synthesis, Saline/Alkaline-tolerance of Pinus thunbergii Parl. Seedlings[D] .外生菌根真菌菌株耐盐碱性筛选以及黑松(Pinus thunbergii Parl.)菌根苗合成、耐盐碱性研究[D] . |
| [21] |
Mycorrhizal studies and their application prospects in China [J].我国菌根学研究进展及其应用展望 [J].
<p>随着科学技术的进步和人们对菌根认识的不断深入，菌根学理论研究日益引起世界各国学者的广泛关注，菌根化应用技术研究也日趋加强。为了及时把握我国菌根学研究的最新进展和现状，阐明我国学者在菌根机理研究和应用领域取得的成绩，本研究归纳了从２００６－２０１０年我国菌根学研究发表的所有科技论文，分析了这些研究论文的性质和特征，在此基础上分别对我国在菌根营养学、菌根生态学、分子生物学技术在菌根学中的应用和菌根对植物耐受胁迫能力等方面的研究成果进行了论述；探讨了我国在利用菌根真菌开展育苗造林和食用菌生产方面的进展。结合当前菌根研究在农、林生产上的应用前景，分析当前我国菌根研究及应用中存在的问题和不足，并对今后我国菌根学的发展方向进行了展望。</p>
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| [22] |
Mycorrhizal inoculant alleviates salt stress in Sesbania aegyptiaca and Sesbania grandiflora under field conditions: Evidence for reduced sodium and improved magnesium uptake [J].
Abstract A field experiment was conducted to examine the effect of the arbuscular mycorrhizal fungus Glomus macrocarpum and salinity on growth of Sesbania aegyptiaca and S. grandiflora. In the salt-stressed soil, mycorrhizal root colonisation and sporulation was significantly higher in AM-inoculated than in uninoculated plants. Mycorrhizal seedlings had significantly higher root and shoot dry biomass production than non-mycorrhizal seedlings grown in saline soil. The content of chlorophyll was greater in the leaves of mycorrhiza-inoculated as compared to uninoculated seedlings. The number of nodules was significantly higher in mycorrhizal than non-mycorrhizal plants. Mycorrhizal seedling tissue had significantly increased concentrations of P, N and Mg but lower Na concentration than non-mycorrhizal seedlings. Under salinity stress conditions both Sesbania sp. showed a high degree of dependence on mycorrhizae, increasing with the age of the plants. The reduction in Na uptake together with a concomitant increase in P, N and Mg absorption and high chlorophyll content in mycorrhizal plants may be important salt-alleviating mechanisms for plants growing in saline soil.
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| [23] |
Elemental composition of arbuscular mycorrhizal fungi at high salinity [J].
We investigated the elemental composition of spores and hyphae of arbuscular mycorrhizal fungi (AMF) collected from two saline sites at the desert border in Tunisia, and of Glomus intraradices grown in vitro with or without addition of NaCl to the medium, by proton-induced X-ray emission. We compared the elemental composition of the field AMF to those of the soil and the associated plants. The spores and hyphae from the saline soils showed strongly elevated levels of Ca, Cl, Mg, Fe, Si, and K compared to their growth environment. In contrast, the spores of both the field-derived AMF and the in vitro grown G. intraradices contained lower or not elevated Na levels compared to their growth environment. This resulted in higher K:Na and Ca:Na ratios in spores than in soil, but lower than in the associated plants for the field AMF. The K:Na and Ca:Na ratios of G. intraradices grown in monoxenic cultures were also in the same range as those of the field AMF and did not change even when those ratios in the growth medium were lowered several orders of magnitude by adding NaCl. These results indicate that AMF can selectively take up elements such as K and Ca, which act as osmotic equivalents while they avoid uptake of toxic Na. This could make them important in the alleviation of salinity stress in their plant hosts.
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| [24] |
Effects of arbuscular mycorrhizal fungi on salinity tolerance of Lagerstroemia indica [J].丛枝菌根真菌对紫薇耐盐性的影响 [J]. |
| [25] |
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| [26] |
Influence of inoculating Arbuscular Mycorrhizal Fungi on growth and salinity tolerance parameters of maize plants [J].盐胁迫下AM真菌对玉米生长及耐盐生理指标的影响 [J].
在自然盐渍土壤上和人工模拟盐胁迫条件下， 采用盆栽方法研究了长期(86天)和短期(1周)盐胁迫条件下丛枝菌根真菌对玉米植株生长和耐盐生理指标的影响。 结果表明： 在自然盐渍土壤和人工模拟长期盐胁迫条件下， 菌根真菌显著提高了玉米的相对产量； 在短期盐胁迫条件下， 接种菌根真菌处理的玉米叶片细胞质膜透性低于不接种
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| [27] |
Effects of Arbuscular Mycorrhiza Fungi (AMF) on the plant growth, fruit yield, and fruit quality of cucumber under salt stress [J].丛枝菌根真菌对盐胁迫下黄瓜植株生长、果实产量和品质的影响 [J].
采用有机基质栽培，选用盐敏感黄瓜品种‘津春2号’为试验材料，研究了丛枝菌根真菌(AMF)对盐胁迫下黄瓜植株生长、矿质营养吸收、果实品质和产量的影响.结果表明：接种AMF可以有效促进黄瓜植株生长和对矿质营养的吸收，提高果实产量和改善蔬菜营养品质；盐胁迫下，黄瓜生长受到抑制，植株体内N、P、K、Cu、Zn含量减少和K<sup>+</sup>/Na<sup>+</sup>降低，果实产量和可溶性蛋白、总糖、Vc、硝酸盐含量下降；接种AMF可缓解盐胁迫对黄瓜生长的抑制作用，使植株体内N、P、K、Cu和Zn含量分别比对照提高7.3%、11.7%、28.2%、13.5%和9.9%，K<sup>+</sup>/Na<sup>+</sup>、果实产量、可溶性蛋白、总糖、Vc含量明显提高，果实硝酸盐含量显著降低.表明AMF可通过促进盐胁迫下黄瓜植株对矿质营养的吸收，促进植株生长，增强植株对盐胁迫的耐性，进而提高其产量和改善营养品质.
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| [28] |
Effect of Arbuscular Mycorrhizal Fungi on nutrition absorbing and ion damage in tomato under salt stress [J].盐渍条件下丛枝菌根真菌对番茄营养吸收及离子毒害的影响 [J].
为探究盐渍条件下丛枝菌根真菌对番茄营养吸收及离子毒害的作用,采用盆栽试验研究了不同浓度NaCl(0.5%和1%)胁迫下,接种丛枝菌根真菌Glomus mosseae-2对番茄营养吸收的影响。结果表明:在盐胁迫下,番茄接种Glomus mosseae-2,显著提高了地上部及根系N、P、K+和Ca2+的含量,显著降低Na+含量,对Cl-含量虽有减少但无显著影响。接种后还显著影响盐胁迫下植株的营养吸收及平衡,增加地上部及根系K+/Na+、P/Na+、Ca2+/Na+及根系P/Cl-值。这些比值与植株总干质量均呈显著正相关,其中与K+/Na+、P/Na+、Ca2+/Na+相关性最大。接菌番茄耐盐性提高与AMF改善植株营养状况尤其是提高K、P含量,保持较高K+/Na+、P/Na+、Ca2+/Na+比值、降低植株Na+含量从而降低Na+对植株的毒害作用有关。
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| [29] |
Effects of Arbuscular Mycorrhizal Fungi(AMF)on seedling growth and Na+、K+、Ca2+、Mg2+ contents and distribution in asparagus under salt stress [J].丛枝菌根真菌(AMF)对盐胁迫下芦笋幼苗生长及体内Na+、K+、Ca2+、Mg2+含量和分布的影响 [J].
以芦笋盐敏感品种‘NJ978’为材料,采用盆栽试验,研究了接种丛枝菌根真菌(AMF)对Na Cl胁迫下芦笋幼苗生长及体内Na+、K+、Ca2+、Mg2+吸收和分布的影响。结果表明:在Na Cl胁迫下,幼苗株高、鲜重、干重均显著降低,接种AMF可以有效缓解盐胁迫对芦笋幼苗生长的抑制;Na Cl处理的芦笋幼苗根系和地上部Na+含量显著高于对照,K+、Ca2+、Mg2+的含量则显著减少;AMF+Na Cl处理的芦笋幼苗根系K+、Ca2+、Mg2+含量与Na Cl处理相比,分别增加了76.9%、23.1%和22.5%,而Na+含量则减少了27.4%;AMF+Na Cl处理的芦笋幼苗地上部K+、Ca2+、Mg2+含量与Na Cl处理相比,分别增加了58.4%、50.4%和76.0%,而Na+含量则减少了42.3%。与Na Cl处理相比,接种AMF可以降低盐胁迫下芦笋幼苗根系和地上部Na+/K+、Na+/Ca2+、Na+/Mg2+,提高根系选择吸收性ASK,Na、ASCa,Na、ASMg,Na和根系向地上部的选择运输性TSK,Na、TSCa,Na、TSMg,Na。由此表明,盐胁迫下接种AMF可以通过调节芦笋体内的离子平衡,从而缓解盐胁迫对植株的伤害。
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| [30] |
Contribution of Glomus intraradices inoculation to nutrient acquisition and mitigation of ionicimbalance in NaCl-stressed Trigonella foenum-graecum [J].
The study aimed to investigate the effects of an AM fungus ( Glomus intraradices Schenck and Smith) on mineral acquisition in fenugreek ( Trigonella foenum-graecum ) plants under different levels of salinity. Mycorrhizal (M) and non-mycorrhizal (NM) fenugreek plants were subjected to four levels of NaCl salinity (0, 50, 100, and 200聽mM NaCl). Plant tissues were analyzed for different mineral nutrients. Leaf senescence (chlorophyll concentration and membrane permeability) and lipid peroxidation were also assessed. Under salt stress, M plants showed better growth, lower leaf senescence, and decreased lipid peroxidation as compared to NM plants. Salt stress adversely affected root nodulation and uptake of NPK. This effect was attenuated in mycorrhizal plants. Presence of the AM fungus prevented excess uptake of Na + with increase in NaCl in the soil. It also imparted a regulatory effect on the translocation of Na + ions to shoots thereby maintaining lower Na + shoot:root ratios as compared to NM plants. Mycorrhizal colonization helped the host plant to overcome Na + -induced Ca 2+ and K + deficiencies. M plants maintained favorable K + :Na + , Ca 2+ :Na + , and Ca 2+ :Mg 2+ ratios in their tissues. Concentrations of Cu, Fe, and Zn 2+ decreased with increase in intensity of salinity stress. However, at each NaCl level, M plants had higher concentration of Cu, Fe, Mn 2+ , and Zn 2+ as compared to NM plants. M plants showed reduced electrolyte leakage in leaves as compared to NM plants. The study suggests that AM fungi contribute to alleviation of salt stress by mitigation of NaCl-induced ionic imbalance thus maintaining a favorable nutrient profile and integrity of the plasma membrane.
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| [31] |
Some important physiological selection criteria for salt tolerance in plants [J].
Undoubtedly, plant breeders have made a significant achievement in the past few years, improving salinity tolerance in a number of potential crops using artificial selection and conventional breeding approaches, although molecular biology approaches are currently being intensively pursued for achieving this goal. However, most of the selection procedures used so far, were based merely on differences in agronomic characters. Agronomic characters represent the combined genetic and environmental effects on plant growth, and include the integration of the physiological phenomena conferring salinity tolerance. In fact, physiological criteria are able to supply more reliable information than agronomic characters. Although there are large numbers of reports in the literature mainly dealing with water relations, photosynthesis, and accumulation of various inorganic ions and organic metabolites in individual crops, there is little information available on the use of these attributes as selection criteria for improving salt tolerance through selection and breeding programs. In this review, the major adaptive components of salt tolerance such as osmotic adjustment, photosynthesis, water relations and ion relations are reviewed. In view of the complexity of salt tolerance and its great variation at intra-specific and inter-specific levels, it is difficult to identify single criteria, which could be used as effective selection targets. Rather it is most meaningful if physiological and biochemical indicators for individual species are determined rather than generic indicators.
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| [32] |
Effects of arbuscular mycorrhizal fungus Glomus mosseae on the growth characteristics of Festuca arundinacea under salt stress conditions [J].AM真菌摩西球囊霉对盐胁迫条件下高羊茅生长特性的影响 [J].
随着全球变化,土壤次生盐渍化日益加重,直接影响到植物的生长发育。高羊茅是重要草坪绿化植物,如何提高其耐盐性是当前亟待解决的问题之一。本研究旨在前期试验的基础上,评价丛枝菌根(arbuscular mycorrhizal, AM)真菌改善高羊茅耐盐性的效应,探索AM真菌增强高羊茅耐盐性的作用机制。在盆栽条件下,对高羊茅接种摩西球囊霉并用不同浓度NaCl(0%,0.8%,1.2%和1.6%)溶液进行处理。结果表明,接种摩西球囊霉能增加高羊茅叶片抗氧化酶(SOD、POD和CAT)活性和抗氧化剂(抗坏血酸)含量、渗透调节物质(可溶性糖和脯氨酸)含量、矿质元素(N、P、S、Zn、K、Ca和Mg)含量、K/Na、Mg/Na、Ca/Na和植物内源激素脱落酸(ABA)、细胞分裂素(IPA)、吲哚乙酸(IAA)和赤霉素(GA)含量;降低丙二醛(MDA)、Na<sup>+</sup>、Cl<sup>-</sup>含量和膜透性。认为AM 真菌能通过增强植物抗氧化系统的反应, 降低氧化胁迫造成的伤害,减缓Na<sup>+</sup>和Cl<sup>-</sup>毒害,改善养分的吸收,强化渗透调节作用,维持激素平衡等来提高其耐盐能力。
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| [33] |
Arbuscular Mycorrhizal Fungal application to improve growth and tolerance of wheat (Triticum aestivum L.) plants grown in saline soil [J].
A pot experiment was conducted to examine the effects of three different arbuscular mycorrhizal fungi, Glomus mosseae, G. deserticola and Gigaspora gergaria , on growth and nutrition of wheat ( Triticum aestivium L. cv. Henta) plants grown in saline soil. Under saline condition, mycorrhizal inoculation significantly increased growth responses, nutrient contents, acid and alkaline phosphatases, proline and total soluble protein of wheat plants compared to non-mycorrhizal ones. Those stimulations were related to the metabolic activity of the each mycorrhizal fungus. The localization of succinate dehydrogenase 鈥淪DH鈥 (as a vital stain for the metabolically active fungus) in the arbuscular mycorrhizal fungi was variable. In general, mycorrhizal shoot plant tissues had significantly higher concentrations of P, N, K and Mg but lower Na concentration than those of non-mycorrhizal plants. In saline soil, growth and nutrition of wheat plants showed a high degree of dependency on mycorrhizal fungi (especially G. mosseae ). The use of the nitroblue tetrazolium chloride method as a vital stain for SDH activity showed that all the structures of mycorrhizal infections in the wheat plant estimated by the trypan blue staining (non-vital stain) were not metabolically active. Interestingly, the reduction in Na uptake along with associated increases in P, N and Mg absorption and high proline, phosphatase activities and chlorophyll content in the mycorrhizal plants could be important for salt alleviation in plants growing in saline soils.
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| [34] |
Ruiz-Lozano J M. Salinity stress alleviation using arbuscular mycorrhizal fungi: A review [J].
Salinity is one of the most severe environmental stress as it decreases crop production of more than 20% of irrigated land worldwide. Hence, it is important to develop salt-tolerant crops. Understanding the mechanisms that enable plant growth under saline conditions is therefore required. Acclimation of plants to salinized conditions depends upon activation of cascades of molecular networks involved in stress sensing, signal transduction, and the expression of specific stress-related genes and metabolites. The stress signal is first perceived at the membrane level by the receptors and then transduced in the cell to switch on the stress-responsive genes which mediate stress tolerance. In addition to stress-adaptative mechanisms developed by plants, arbuscular mycorrhizal fungi have been shown to improve plant tolerance to abiotic environmental factors such as salinity. In this review, we emphasize the significance of arbuscular mycorrhizal fungi alleviation of salt stress and their beneficial effects on plant growth and productivity. Although salinity can affect negatively arbuscular mycorrhizal fungi, many reports show improved growth and performance of mycorrhizal plants under salt stress conditions. These positive effects are explained by improved host plant nutrition, higher K + /Na + ratios in plant tissues and a better osmotic adjustment by accumulation of compatible solutes such as proline, glycine betaine, or soluble sugars. Arbuscular mycorrhizal plants also improve photosynthetic- and water use efficiency under salt stress. Arbuscular mycorrhizal plants enhance the activity of antioxidant enzymes in order to cope with the reactive oxygen species generated by salinity. At the molecular level, arbuscular mycorrhizal symbiosis regulates the expression of plant genes involved in the biosynthesis of proline, of genes encoding aquaporins, and of genes encoding late embryogenesis abundant proteins, with chaperone activity. The regulation of these genes allows mycorrhizal plants to maintain a better water status in their tissues. Gene expression patterns suggest that mycorrhizal plants are less strained by salt stress than non-mycorrhizal plants. In contrast, scarce information is available on the possible regulation by the arbuscular mycorrhizal symbiosis of plant genes encoding Na + /H + antiporters or cyclic nucleotide-gated channels. These genes encode proteins with a key role in the regulation of uptake, distribution and compartimentation of sodium and other ions within the plant, and are major determinants for the salt sensitiveness of a plant. Thus, we propose that investigating the participation of cation proton antiporters and cyclic nucleotide-gated channels on arbuscular mycorrhizal symbiosis under salinity is a promising field that should shed further light on new mechanisms involved in the enhanced tolerance of mycorrhizal plants to salt stress.
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| [35] |
Effect of Arbuscular Mycorrhizal Fungi on growth and physiology of elaeaguus augustifolia seedlings subjected to salinity stress [J].盐碱胁迫下AM真菌对沙枣苗木生长和生理的影响 [J].
<b>[目的]</b> 研究盐碱胁迫下丛枝菌根(AM)真菌对沙枣苗木的生长和生理的影响,以期探索AM真菌提高沙枣苗木耐盐碱机制,为菌根化沙枣苗木在盐碱地推广应用提供理论基础。<b>[方法]</b> 采用盆栽法研究了4种不同土壤盐碱度下分别接种根内球囊霉和摩西球囊霉对沙枣苗木的生长影响,并对沙枣苗木的光合特性、Na<sup>+</sup>和K<sup>+</sup>含量、丙二醛含量、脯氨酸含量等各项生理指标进行测定。<b>[结果]</b> 2种AM真菌均能与沙枣苗木建立共生关系,且GI处理对苗木的侵染率显著高于接种GM处理,但随着土壤中盐浓度增加,沙枣苗木菌根侵染率有所降低。在同一盐碱度下接种AM真菌可显著促进沙枣幼苗的生长,在中度盐碱胁迫下(含盐量1.56%,pH 9.52),接种GI和GM的沙枣苗木株高分别较未接种AM真菌植株增加了20.07%,9.68%,植株干生物量显著增加;AM真菌可显著提高盐碱胁迫下沙枣幼苗叶片叶绿素含量和光合生理特性,其叶片净光合速率<i>P</i><sub>n</sub>、蒸腾速率<i>Tr</i>、气孔导度<i>G</i><sub>s</sub>、胞间二氧化碳浓度<i>C</i><sub>i</sub>均显著高于未接种AM真菌处理的幼苗(<i>P</i><0.05)。接种GI和GM处理植株叶片组织内SOD,CAT和POD酶活性显著高于对照处理,但根系及叶片组织内丙二醛含量显著低于对照处理的植株,而其脯氨酸含量却都表现出显著提高。接种AM真菌沙枣根系和叶片中Na<sup>+</sup>含量较未接种处理植株显著下降,K<sup>+</sup>含量和K<sup>+</sup>/Na<sup>+</sup>比值显著提高。<b>[结论]</b> 接种AM真菌能显著提高沙枣苗木耐盐碱能力。接种根内球囊霉的沙枣苗木的生长及抗盐碱胁迫能力的各项生理指标均显著高于接种摩西球囊霉处理的苗木,表明根内球囊霉在盐碱地改良方面具有很好的推广应用前景。
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| [36] |
Effects of two different AMF species on growth and nutrient content of pepper seedlings grown under moderate salt stress [J].
This study was carried out to determine the effects of different Arbuscular Mycorrhizal Fungi (AMF) species on the growth and nutrient contents of pepper seedlings (cv. Demre) grown under moderate salt stress. Two different mychorrhizas (Glomus intraradices and Gigaspora margarita) were tested on a growing media containing moderate salt stress (75 ppm NaCl). The study was replicated four times with 8 plants in each replicate. At the end of the study, some nutrients such as P, K, Ca, and Na and plant growth parameters such as shoot height, stem diameter, root length, and dry and fresh weights of shoots and roots were investigated. Saline condition had negative effects on the seedlings. Both AMF species had positive effects on salt tolerance based on the plant growth parameters and nutrient contents. G. intraradices caused better response in seedling development compared to G. margarita, though insignificantly. Key words: Arbuscular mychorrhizal fungi, NaCl nutrient, pepper seedling growth.
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| [37] |
Effects of AM Fungi on Salt Resistance of Different Types of Halophytes[D] .AM真菌对不同盐生植物抗盐性的影响[D] . |
| [38] |
Preinoculation of lettuce and onion with VA mycorrhizal fungi reduces deleterious effects of soil salinity [J].
The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils alleviates salt effects on growth and yield was tested on lettuce ( Lactuca sativa L.) and onion ( Allium cepa L.). A second hypothesis was that fungi isolated from saline soil are more effective in counteracting salt effects than those from nonsaline soil. VAM fungi from high- and low-salt soils were trap-cultured, their propagules quantified and adjusted to a like number, and added to a pasteurized soil mix in which seedlings were grown for 3鈥4 weeks. Once the seedlings were colonized by VAM fungi, they were transplanted into salinized (NaCl) soil. Preinoculated lettuce transplants grown for 11 weeks in the saline soils had greater shoot mass compared with nonVAM plants at all salt levels [2 (control), 4, 8 and 12 dS m 鈭1 ] tested. Leaves of VAM lettuce at the highest salt level were significantly greener (more chlorophyll) than those of the nonVAM lettuce. NonVAM onions were stunted due to P deficiency in the soil, but inoculation with VAM fungi alleviated P deficiency and salinity effects; VAM onions were significantly larger at all salt levels than nonVAM onions. In a separate experiment, addition of P to salinized soil reduced the salt stress effect on nonVAM onions but to a lesser extent than by VAM inoculation. VAM fungi from the saline soil were not more effective in reducing growth inhibition by salt than those from the nonsaline site. Colonization of roots and length of soil hyphae produced by the VAM fungi decreased with increasing soil salt concentration. Results indicate that preinoculation of transplants with VAM fungi can help alleviate deleterious effects of saline soils on crop yield.
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| [39] |
Expression analysis of LeNHX1 gene in mycorrhizal tomato under salt stress [J].
The plant growth, stem sap flow, Na + and Cl 61 content, and the expression of vacuolar Na + /H + antiporter gene ( LeNHX1 ) in the leaves and roots of tomato under different NaCl stresses (0.5% and 1%) were studied to analyze the effect of arbuscular mycorrhizal fungi (AMF) on Na + and Cl 61 accumulation and ion exchange. The results showed that arbuscular mycorrhizal (AM) plant growth and stem sap flow increased and salt tolerance improved, whereas Na + and Cl 61 accumulated. Na + significantly decreased, and no significant decline was detected in Cl 61 content after AMF inoculation compared with the non-AM plants. The LeNHX1 gene expression was induced in the AM and non-AM plants by NaCl stress. However, AMF did not improve the LeNHX1 level, and low expression was observed in the AM tomato. Hence, the mechanism that reduced the Na + damage to tomato induced by AMF has little relation to LeNHX1 , which can export Na + from the cytosol to the vacuole across the tonoplast.
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| [40] |
Analysis of expression of aquaporins and Na+/H+, transporters in tomato colonized by arbuscular mycorrhizal fungi and affected by salt stress [J].
Among the proteins functioning in salt tolerance of plants, Na + /H + transporters and aquaporins appear to be of paramount importance. The present study compares expression of Na + /H + transporter and aquaporin genes in tomato colonized by arbuscular mycorrhizal fungi (AMF) and in non-colonized controls under NaCl stress. As revealed by Northern analyses and in situ hybridizations, expression of two Na + /H + transporter genes is not significantly affected by salt stress or by colonization of the plants with AMF. In contrast, transcript levels of both a tonoplast and a plasmalemma aquaporin gene are reduced by salt stress, and this effect is distinctly enhanced by colonization of the tomato roots with AMF. In leaves, colonization of tomato by AMF results in a drastic increase of the mRNA of all three aquaporin genes assayed under salt stress. Aquaporins are known to significantly contribute to water movement in plants. The results presented here indicate that AMF controls aquaporin expression and thereby presumably regulates water flow in tomato under salt stress.
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| [41] |
VA) mycorrhizae improve salinity tolerance in pre-inoculation subterranean clover (Trifolium subterraneum) seedlings [J].
Effects of the mycorrhizal fungus Glomus intraradices on establishment of subterranean clover (Trifolium subterraneum L.) seedlings in saline conditions were studied in a glasshouse experiment. Growth and nutrient uptake were determined 10, 20 and 30 days after transplanting of mycorrhizal and nonmycorrhizal matched seedlings into soils with five different levels of salinity. Mycorrhizal plants had greater shoot and root dry weight than nonmycorrhizal plants. The enhancement in seedling dry weight due to mycorrhizal fungi was greater under high salinity levels. The detrimental effects of salinity stress on plant growth were appeared immediately after application low salinity stress to nonmycorrhizal plants (3.5 dS/m), but it was only observed in mycorrhizal plants at 7.5 dS/m and above. Mycorrhizal fungi increased P concentrations in shoots and roots compared with nonmycorrhizal plants particularly at 12 dS/m. Root K/Na ratio was also increased in mycorrhizal plants, possibly contributing to salinity tolerance. Calculation of mycorrhizal responses in terms of plant dry weight, P and K contents showed that the beneficial effects of mycorrhizal fungi on seedling salinity tolerance are due to different mechanisms at different stage of growth: increased P uptake during early growth and increased K uptake at the later stages. Results are discussed in the context of application of mycorrhizal inoculation to revegetation of salt affected lands.
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| [42] |
Effects of Arbuscular Mycorrhizal Fungi on the growth of reeds in wetland soils with different salt content [J].丛枝菌根真菌对不同含盐量湿地土壤中芦苇生长的影响 [J].
采用温室盆栽实验的方法,研究接种Claroideoglomus etunicatum(CE)、Rhizophagus intraradices(RI)、Funneliformis mosseae(FM)和Glomus versiforme(GV)对非盐渍化和盐渍化湿地土壤上芦苇(Phragmites australis)菌根侵染率、生物量、矿质营养吸收、C∶N∶P生态化学计量比和Na+、Cl-含量的影响,旨在为我国湿地生态系统的生态恢复和盐碱化修复提供理论依据和技术支持.结果表明,在2种湿地土壤上4种AM真菌的平均菌根侵染率为2.5％ ～ 38％,接种CE的侵染率显著高于其它接种处理;盐渍化湿地土壤上芦苇菌根侵染率与非盐渍化湿地土壤间无显著性差异,非盐渍化湿地土壤芦苇生物量、矿质营养元素的吸收显著高于盐渍化湿地土壤,而Na+和Cl-的含量显著低于盐渍化湿地土壤.对于非盐渍化湿地土壤,接种GV处理显著增加了芦苇地上部的干重,促进了芦苇地上部对N、P、K、Ca和Mg等5种营养元素的吸收,接种GV和RI则显著促进了芦苇根部对P和K的吸收;4种接种处理显著降低了芦苇地上部N∶P,接种FM和GV显著降低了根部C:N和C∶P;4种接种处理也显著降低了芦苇地上部Cl-的含量,接种RI处理显著降低了芦苇地上部Na+的含量.对于盐渍化湿地土壤,4种接种处理对芦苇生物量、矿质营养吸收和Na+、Cl-的含量均没有显著性影响.结果也表明,AM真菌对于不同含盐量湿地土壤芦苇生长的影响表现出不同的菌根效应,在非盐渍化湿地土壤上对芦苇生长的有益作用明显好于盐渍化湿地土壤.应结合相应的技术措施进一步通过野外实地实验筛选接种效果好的AM真菌菌种,探讨菌根技术对不同含盐量湿地土壤上芦苇生长的实际作用.
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| [43] |
Research advance of plant osmoregulation [J].植物渗透调节的研究进展 [J].
介绍了渗透调节的过程，并从植物信号转导、渗透调节物质、水通道蛋白等方面对植物渗透调节研究进展进行了探讨。
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| [44] |
Soil and fertilizer phosphorus: Effects on plant P supply and mycorrhizal development [J].
Plants require adequate P from the very early stages of growth for optimum crop production. Phosphorus supply to the crop is affected by soil P, P fertilizer management and by soil and environmental conditions influencing P phytoavailability and root growth. Phosphorus uptake in many crops is improved by associations with arbuscular mycorrhizal fungi. Cropping system and long-term input of P through fertilizers and manures can influence the amount and phytoavailability of P in the system and the development of mycorrhizal associations. Optimum yield potential requires an adequate P supply to the crop from the soil or from P additions. Where early-season P supply is low, P fertilization may improve P nutrition and crop yield potential. Alternately, under low-P conditions, encouragement of arbuscular mycorrhizal associations may enhance P uptake by crops early in the growing season, improving crop yield potential and replacing starter fertilizer P applications. Soil P supply that exceeds P requirements of t...
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| [45] |
Effects of Arbuscular Mycorrhizal Fungi and plant symbiosis on plant water relation and its mechanism [J].丛枝菌根真菌与植物共生对植物水分关系的影响及机理 [J]. |
| [46] |
Quantification of mycorrhizal water uptake via high-resolution on-line water content sensors [J]. |
| [47] |
Alleviation of salt stress by arbuscular-mycorrhizal Glomus species in Lactuca sativa plants [J].
Improved salt tolerance of mycorrhizal plants is commonly attributed to their better mineral nutrition, particularly phosphorus. However, the effect of arbuscular-mycorrhizal (AM) fungi on salt tolerance may not be limited to this mechanism. The possibility that non-nutritional effects of AM fungi, based on proline accumulation or increased photosynthesis and related parameters, can influence the tolerance of lettuce (Lactuca sativa) to salinity was investigated. In pot experiments in controlled environment chambers, lettuce plants were exposed to 3, 4 or 5 g NaCl/kg dry soil and inoculated with one of three AM fungi or given P fertilizers. The salt-treated AM plants produced greater root and shoot dry weights than unfertilized or P-fertilized non-AM controls. With increasing salinity, both shoot and root dry weights were reduced, but this decrease was greater in uninoculated plants. In particular, shoot dry weight was not reduced in G. fasciculatum-colonized plants as a consequence of salt, whereas in uninoculated plants it was reduced by about 35% at the highest salt level. Proline accumulation was considerably lower for P-amended non-AM plants and for AM plants except for G. mosseae-colonized plants, than was the case for unamended plants. Transpiration, carbon dioxide exchange rate (CER), stomatal conductance and water use efficiency (WUE) were higher in mycorrhizal plants. At 5 g NaCl/kg, both photosynthesis and WUE in the inoculated plants was >100% greater than in the uninoculated plants. The contents of phosphorus of P-fertilized non-AM plants was similar to or higher than those of G. mosseae- and G. fasciculatum-colonized plants. Plants colonized by G. deserticola had the highest P content regardless of salt level. Hence, the effect of G. mosseae and G. fasciculatum on salt tolerance could not be attributed to a difference in the P content. The mechanisms by which these two fungi alleviated salt stress appeared to be based on physiological processes (inc
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| [48] |
Effect of AM fungi on water and nutrition status of corn plants under salt stress [J].盐胁迫下丛枝菌根真菌对玉米水分和养分状况的影响 [J]. |
| [49] |
Salt stress signals shape the plant root [J].
Abstract Plants use different strategies to deal with high soil salinity. One strategy is activation of pathways that allow the plant to export or compartmentalise salt. Relying on their phenotypic plasticity, plants can also adjust their root system architecture (RSA) and the direction of root growth to avoid locally high salt concentrations. Here, we highlight RSA responses to salt and osmotic stress and the underlying mechanisms. A model is presented that describes how salinity affects auxin distribution in the root. Possible intracellular signalling pathways linking salinity to root development and direction of root growth are discussed. These involve perception of high cytosolic Na+ concentrations in the root, activation of lipid signalling and protein kinase activity and modulation of endocytic pathways. Copyright 脗 2011 Elsevier Ltd. All rights reserved.
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| [50] |
Review on stress-resistance of phytohormone [J].
植物激素抗逆性研究进展 [J].
脱落酸、乙烯、细胞分裂素、多胺等激素在激素抗逆研究中备受关注,文中运用大量事实阐述了上述几种激素在抵抗逆境(水分胁迫、温度胁迫、盐胁迫等)方面的生理反应机制,目的是为化控技术在生产上的运用提供理论基础,而且可为培育筛选抗旱、抗寒、抗盐等植物优良品种提供参考。
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| [51] |
Effect of Arbuscular Mycorrhizal Fungi on tomato endogenous under NaCl stress [J].丛枝菌根真菌对NaCl胁迫下番茄内源激素的影响 [J].
采用盆栽试验研究了不同浓度NaCl(0.3%、0.6%和1.0%)胁迫下,接种丛枝菌根真菌Glomusmosseae-2对番茄内源激素的影响。结果表明:(1)盐胁迫下,植株生长受抑,生长促进物质IAA、GA3和Zeatin含量下降,生长抑制物质ABA含量增加,接种Glomus mosseae-2增加了植株干物质量和这些激素的含量;(2)菌根形成过程中,Glomus mosseae-2参与调节内源激素平衡,降低了叶片ABA/IAA、ABA/GA3、ABA/Zeatin及ABA/(IAA+GA3+Zeatin)的比值;(3)气孔导度(gs))和ABA/Zeatin值呈极显著负相关,同一盐浓度胁迫下,接菌株有较高gs和较低的ABA/Zeatin值。ABA和Zeatin共同调节气孔对盐胁迫的响应,维持接菌株较高的气孔导度,增强了番茄的耐盐性。
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| [52] |
Morphogenetic modifications induced by the mycorrhizal fungus Glomus strain E3 in the root system of Allium porrum L [J].
SUMMARY Morphometric analysis, modelling and histological techniques were used to study root morphogenesis in nonmycorrhizal and mycorrhizal plants of Allium porrum infected by a Glomus sp., strain E 3 , during the first 105 days after sowing. They showed that morphogenetic changes were induced by the fungus in the root system of the host. Adventitious roots of mycorrhizal plants became more numerous and shorter than those of controls, as mycorrhizal infection proceeded. Increase in number was fitted by logistic curves in mycorrhizal and control plants; increase in length was fitted in both cases by logistic curves. Mycorrhizal roots became progressively more branched than controls: branching increased linearly with time in mycorrhizas, whereas in the controls it showed an almost constant frequency from day 49 onwards and was fitted by a logistic curve. There was a significant depression of mitotic index demonstrated in the apical meristems of vesicular-arbuscular mycorrhizas.
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| [53] |
Arbuscular mycorrhizal fungi can alter some root characters and physiological status in trifoliate orange (Poncirus trifoliata, L. Raf.) seedlings [J].
Citrus plants strongly depend on mycorrhizal symbiosis because of less or no root hairs, but few reports have studied if their root traits and physiological status could be altered by different arbuscular mycorrhizal fungi (AMF). In a pot experiment we evaluated the effects of three AMF species, Glomus mosseae , G . versiforme and Paraglomus occultum on the root traits and physiological variables of the trifoliate orange ( Poncirus trifoliata L. Raf.) seedlings. Root mycorrhizal colonization was 58–76% after 18002days of inoculation. AMF association significantly increased plant height, stem diameter, leaf number per plant, shoot and root biomass. Mycorrhizal seedlings also had higher total root length, total root projected area, total root surface area and total root volume but thinner root diameter. Among the three AMFs, greater positive effects on aboveground growth generally ranked as G . mosseae 02>02 P . occultum 02>02 G . versiforme, whilst on root traits as G . mosseae 02≈02 P . occultum 02>02 G . versiforme . Compared to the non-mycorrhizal seedlings, contents of chlorophyll, leaf glucose and sucrose, root soluble protein were significantly increased in the mycorrhizal seedlings. In contrast, root glucose and sucrose, leaf soluble protein, and activity of peroxidase (POD) in both leaves and roots were significantly decreased in the mycorrhizal seedlings. It suggested that the improvement of root traits could be dependent on AMF species and be related to the AMF-induced alteration of carbohydrates and POD.
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| [54] |
Effects of salt stress on plants and the mechanism of salt tolerance [J].盐胁迫对植物的影响及植物的抗盐机理 [J].
盐是影响植物生长和产量的主要 环境因子之一,根据国内外最新的研究资料,从盐胁迫对植物的生长、水分关系、叶片解剖学、光和色素及蛋白、脂类、离子水平、抗氧化酶及抗氧化剂、氮素代 谢、苹果酸盐代谢、叶绿体超微结构的影响,及影响光合作用的机制等方面入手,对植物盐胁迫研究现状及进展情况进行了综述,旨在为开展植物抗盐机理研究、选 育培育耐盐植物新品种提供依据。
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| [55] |
The researches on osmotic-adjustments of plants under salt stress [J].植物在盐害下的渗透调节 [J].
植物遭受盐胁迫时的重要反应就是体内产生大量的渗透调节物质：无机盐离子和可溶性有机化合物．大量研究证明，有机物是植物在盐境下最重要的渗透调节剂，它无毒，且对稳定细胞的结构和功能有重要的作用。对有关渗透调节剂的基因调控机制的最新进展作了综合论述．
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| [56] |
Effects of salt stress on osmotic adjustment substances in different halophytes [J].盐胁迫下不同盐生植物渗透调节的生理响应 [J].
研究了3种柳树（Salix）、3种柽柳（Tamarix）和2种白刺（Nitraria）的1年生苗在不同浓度（0、100、200、300、400mmol／L）NaCl胁迫30d后渗透调节物质含量的变化。结果表明：盐胁迫后8个树种叶片中积累脯氨酸和可溶性糖抵御盐胁迫，柳树和白刺中的可溶性蛋白增加，可溶性蛋白不是甘蒙柽柳和刚毛柽柳的主要有机渗透调节物质；各树种根茎叶中Na＋和Cl-显著增加，白刺的Na＋和Cl-的质量分数明显高于柳树和柽柳，3种柳树K＋下降，柽柳和白刺各部位K＋种间差别较大，各离子在不同植物的不同部位的分布存在差异，K＋／Na-总体来说随着盐浓度增加而降低。可见，不同渗透调节物质在不同盐生植物中的重要性是不同的，植物的耐盐机理和种间差异对植物在盐胁迫下用于渗透调节的主要渗透调节物质及其含量变化以及在各器官组织中的分布有一定的影响。
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| [57] |
Increasing NaCl-salt tolerance of a halophytic plant Phragmites australis by mycorrhizal symbiosis [J].
Through biological inoculation technology, pot greenhouse experiments were conducted in attempt to increase salinity tolerance of a halophytic plants; Phragmites australis; by using arbuscular mycorrhizal (AM) fungus Glomus fasciculatum isolated from saline soil. Mycorrhizal and non-mycorrhizal plants were exposed to 0.0, 50, 100, 150, 200, 250 and 300 mM of NaCl. Plant growth was significantly...
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| [58] |
Role of Arbuscular Mycorrhizae in the Alleviation of Ionic, Osmotic and Oxidative Stresses Induced by Salinity in Cajanus cajan(L.) Millsp. (pigeonpea) [J].
Salinity stress causes ion toxicity and osmotic imbalances, leading to oxidative stress in plants. Arbuscular mycorrhizae (AM) are considered bio-ameliorators of saline soils and could develop salinity tolerance in crop plants. Pigeonpea exhibits strong mycorrhizal development and has a high mycorrhizal dependency. The role of AM in enhancing salt tolerance of pigeonpea in terms of shoot and root dry weights, phosphorus and nitrogen contents, K + : Na + , Ca 2+ : Na + ratios, lipid peroxidation, compatible solutes (proline and glycine betaine) and antioxidant enzyme activities was examined. Plants were grown and maintained at three levels of salt (4, 6 and 8 dSm 鈭1 ). Stress impeded the growth of plants, led to weight gain reductions in shoots as well as roots and hindered phosphorus and nitrogen uptake. However, salt-stressed mycorrhizal plants produced greater root and shoot biomass, had higher phosphorus and nitrogen content than the corresponding uninoculated stressed plants. Salt stress resulted in higher lipid peroxidation and membrane stability was reduced in non-AM plants. The presence of fungal endophyte significantly reduced lipid peroxidation and membrane damage caused by salt stress. AM plants maintained higher K + : Na + and Ca 2+ : Na + ratios than non-AM plants under stressed and unstressed conditions. Salinity induced the accumulation of both proline and glycine betaine in AM and non-AM plants. The quantum of increase in synthesis and accumulation of osmolytes was higher in mycorrhizal plants. Antioxidant enzyme activities increased significantly with salinity in both mycorrhizal and non-mycorrhizal plants. In conclusion, pigeonpea plants responded to an increased ion influx in their cells by increasing the osmolyte synthesis and accumulation under salt stress, which further increased with AM inoculation and helped in maintaining the osmotic balance. Increase in the antioxidant enzyme activities in AM plants under salt stress could be involved in the beneficial effects of mycorrhizal colonization.
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| [59] |
Influence of Arbuscular Mycorrhizal (AM) fungi and salinity on seedling growth, solute accumulation, and mycorrhizal dependency of Jatropha curcas L. [J].
Production of Jatropha curcas as a biodiesel feedstock on marginal lands is growing rapidly. Biomass production on these lands is limited. Hence, the objective of this study was to evaluate the effect of arbuscular mycorrhiza (AM) fungi and salinity (0.1, 0.2, 0.3, 0.4, and 0.5% NaCl) on (1) seedling growth, leaf relative water content (RWC), lipid peroxidation, solute accumulation (proline and sugars), and photosynthetic pigments (Chl a and b ) of Jatropha ; (2) mycorrhizal colonization (%) and mycorrhizal dependency (MD) of Jatropha ; and (3) glomalin content (Bradford reactive soil protein) in soil. Increased soil salinity significantly ( P 02<020.05) decreased AM root colonization ( r 2 02=020.98) of AM-inoculated plants and decreased survival ( r 2 02=020.93) and growth (shoot length, r 2 02=020.89; tap root length, r 2 02=020.93; shoot diameter, r 2 02=020.99; shoot dry weight, r 2 02=020.92; and root dry weight, r 2 02=020.92) of non-AM-inoculated Jatropha . Under salt stress, AM-inoculated Jatropha plants had greater dry weight of shoots and roots, better leaf water status, less leaf membrane damage (low lipid peroxidation activity), higher solute (proline and sugars), and higher leaf chlorophyll concentrations than non-AM-inoculated plants. The mycorrhizal dependency (MD) of Jatropha increased from 12.13 to 20.84% with salinity (0–0.4% NaCl). Root AM colonization (%) and glomalin content in soil were negatively correlated with salinity ( P 02<020.05, r 02=02610.95). We conclude that inoculation with AM fungi lessens the deleterious effect of salt stress on seedling growth parameters under salt levels up to 0.5% NaCl (electrical conductivity of 7.2 dS m 611 ). Inoculation of Jatropha seedlings with AM fungi can promote the establishment of Jatropha under NaCl-induced stress.
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| [60] |
Alleviation of salt stress in citrus seedlings inoculated with mycorrhiza: Changes in leaf antioxidant defense systems [J].
Citrus is a salt-sensitive plant. In the present study, the salt stress ameliorating the effect of arbuscular mycorrhizal fungi through antioxidant defense systems was reported. Three-month-old trifoliate orange (Poncirus trifoliata) seedlings colonized by Glomus mosseae or G. versiforme were irrigated with 0 and 100 mmol NaCl solutions. After 49 days of salinity, mycorrhizal structures were ob...
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| [61] |
Effects of arbuscular mycorrhizal fungi on osmoregulation substance contents and antioxidant enzyme activities of cucumber seedlings under salt stress [J].丛枝菌根真菌对盐胁迫下黄瓜幼苗渗透调节物质含量和抗氧化酶活性的影响 [J]. |
| [62] |
Modulation of polyamine balance in Lotus glaber by salinity and arbuscular mycorrhiza [J].
Abstract In this work we investigated the involvement of Glomus intraradices in the regulation of plant growth, polyamines and proline levels of two Lotus glaber genotypes differing in salt tolerance, after longterm exposure to saline stress. The experiment consisted of a randomized block design with three factors: (1) mycorrhizal treatments (with or without AM fungus); (2) two salinity levels of 0 and 200mM NaCl; and (3) L. glaber genotype. Experiments were performed using stem cuttings derived from L. glaber individuals representing a natural population from saline lowlands. One of the most relevant results was the higher content of total free polyamines in mycorrhized plants compared to non-AM ones. Since polyamines have been proposed as candidates for the regulation of root development under saline situations, it is possible that AM plants (which contained higher polyamine levels and showed improved root growth) were better shaped to cope with salt stress. Colonization by G. intraradices also increased (Spd+Spm)/Put ratio in L. glaber roots. Interestingly, such increment in salt stressed AM plants of the sensitive genotype, was even higher than that produced by salinization or AM symbiosis separately. On the other hand, salinity but not mycorrhizal colonization influenced proline levels in both L. glaber genotypes since high proline accumulation was observed in both genotypes under salt stress conditions. Our results suggest that modulation of polyamine pools can be one of the mechanisms used by AM fungi to improve L. glaber adaptation to saline soils. Proline accumulation in response to salt stress is a good indicator of stress perception and our results suggest that it could be used as such among L. glaber genotypes differing in salt stress tolerance.
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| [63] |
Alleviation of salt-induced adverse impact via mycorrhizal fungi in Ephedra aphylla Forssk [J].
The current investigation was carried out to examine the role of arbuscular mycorrhizal fungi (AMF) in alleviating adverse effects of salt stress in Ephedra aphylla. The plants were exposed to 75 and 150 mM sodium chloride (NaCl) stress with and without application of AMF. Salt stress caused significant decrease in chlorophyll and carotenoid contents; however, the application of AMF restored the pigments content in salt-affected plants. Proline, phenols, and lipid peroxidation were increased with increasing concentration of NaCl, but lower accumulation has been reported in plants treated with AMF. NaCl stress also showed increase in different antioxidant enzymes activities (catalase, ascorbate peroxidase, peroxidase, glutathione reductase, and superoxide dismutase), and further increase was observed in plants treated with AMF. The nutrient uptake, Na+ and Na/K ratio increased and potassium and phosphorus were decreased with increasing concentration of NaCl in the present study. However, the colonization with AMF significantly increased K+ and P and reduced Na+ uptake. It is concluded that presown soil treatment with AMF reduced severity of salt stress in E. aphylla through alterations in physiological parameters, antioxidants and uptake of nutrients.
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| [64] |
Short-term salt tolerance mechanisms in differentially salt tolerant tomato species [J].
Abstract The physiological changes induced by a daily increase of NaCl level, over a period of 4 d, were studied in leaves of the salt-sensitive cultivated tomato species Lycopersicon esculentum and its wild salt-tolerant relative Lycopersicon pennellii. A higher solute contribution to the osmotic adjustment was observed in NaCl-treated leaves of L. pennellii than in those of L. esculentum. This response together with the higher accumulation of inorganic solutes in the wild species and of organic solutes in the cultivated species verified the different salt tolerance mechanisms operating in the two species in the short-term. With regard to the changes induced by salt stress on the free polyamine levels, the putrescine and spermine levels increased with salinity, whereas the spermine levels decreased in both tomato species; nevertheless, the main difference between the two species lays in an earlier and greater accumulation of putrescine induced by salinity in L. pennellii than in L. esculentum. The changes in putrescine levels were associated to changes in amino acids related to its synthesis, and the changes were different in both species. In L. esculentum, the high concentrations of some intermediate compounds (glutamate and arginine) were related to the low accumulation rate of both proline and putrescine. In contrast, in L. pennellii, important reductions in glutamate and arginine levels were found at the end of the salinization period. Moreover, in this last situation, a decline in the putrescine level ran parallel to a high proline accumulation, which suggests that the higher the stress level, the higher the deviation of glutamate to proline occurring in the salt tolerant species. It could be concluded that an early accumulation of the diamine putrescine seems to be associated with salt tolerance in the short-term.
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| [65] |
A comparison of salt resistance of three kinds of Zoysia at different salt concentrations [J].不同盐浓度下3种结缕草的耐盐性比较研究 [J].
<p>以大穗结缕草、沟叶结缕草和日本结缕草为试材，研究了不同浓度ＮａＣｌ（０．２０％，０．４０％，０．６０％，０．８０％）处理４０ｄ后对３种草坪草叶片中保护酶（ＰＯＤ，ＳＯＤ，ＣＡＴ）活性、丙二醛、脯氨酸、叶绿素及可溶性蛋白含量的影响，以确定各自的耐盐性强弱。结果表明，随盐浓度增加，３种草坪草叶片中的保护酶活性、丙二醛、脯氨酸含量呈上升趋势。在０．８０％ 盐浓度下，大穗结缕草叶片中的保护酶活性较高而丙二醛、脯氨酸含量较低；低盐浓度下（＜０．４０％），３种草坪草叶片的叶绿素含量、可溶性蛋白含量随盐浓度升高而升高，高盐浓度下（＞０．６０％），随盐浓度升高而下降。在０．８０％盐浓度下，大穗结缕草叶片的叶绿素及可溶性蛋白含量较高且下降值较小。表明大穗结缕草具有较高的耐盐性。</p>
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| [66] |
Influence of arbuscular mycorrhiza on organic solutes in maize leaves under salt stress [J].
A pot experiment was conducted to examine the effect of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae , on plant biomass and organic solute accumulation in maize leaves. Maize plants were grown in sand and soil mixture with three NaCl levels (0, 0.5, and 1.002g02kg 611 dry substrate) for 5502days, after 1502days of establishment under non-saline conditions. At all salinity levels, mycorrhizal plants had higher biomass and higher accumulation of organic solutes in leaves, which were dominated by soluble sugars, reducing sugars, soluble protein, and organic acids in both mycorrhizal and non-mycorrhizal plants. The relative abundance of free amino acids and proline in total organic solutes was lower in mycorrhizal than in non-mycorrhizal plants, while that of reducing sugars was higher. In addition, the AM symbiosis raised the concentrations of soluble sugars, reducing sugars, soluble protein, total organic acids, oxalic acid, fumaric acid, acetic acid, malic acid, and citric acid and decreased the concentrations of total free amino acids, proline, formic acid, and succinic acid in maize leaves. In mycorrhizal plants, the dominant organic acid was oxalic acid, while in non-mycorrhizal plants, the dominant organic acid was succinic acid. All the results presented here indicate that the accumulation of organic solutes in leaves is a specific physiological response of maize plants to the AM symbiosis, which could mitigate the negative impact of soil salinity on plant productivity.
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| [67] |
Modulation of Aquaporin Genes by the Arbuscular Mycorrhizal Symbiosis in Relation to Osmotic Stress Tolerance [M]. |
| [68] |
Aquaporin and water transport in plant [J].水孔蛋白与植物的水分运输 [J].
水孔蛋白是水专一性通道蛋白,属于膜内在主体蛋白,普遍存在于动、植物及微生物中.其种类繁多、分布广泛,与植物体内水分的快速、高效运输密切相关.就水孔蛋白的发现、结构、类型、分布、生化特性、调节和功能与植物的水分运输进行简单综述.
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| [69] |
How does arbuscular mycorrhizal symbiosis regulate root hydraulic properties and plasma membrane aquaporins in Phaseolus vulgaris, under drought, cold or salinity stresses? [J].
Abstract Here, we evaluated how the arbuscular mycorrhizal (AM) symbiosis regulates root hydraulic properties and root plasma membrane aquaporins (PIP) under different stresses sharing a common osmotic component. Phaseolus vulgaris plants were inoculated or not with the AM fungus Glomus intraradices, and subjected to drought, cold or salinity. Stress effects on root hydraulic conductance (L), PIP gene expression and protein abundance were evaluated. Under control conditions, L in AM plants was about half that in nonAM plants. However, L was decreased as a result of the three stresses in nonAM plants, while it was almost unchanged in AM plants. At the same time, PIP2 protein abundance and phosphorylation state presented the same trend as L. Finally, the expression of each PIP gene responded differently to each stress and was dependent on the AM fungal presence. Differential expression of the PIP genes studied under each stress depending on the AM fungal presence may indicate a specific function and regulation by the AM symbiosis of each gene under the specific conditions of each stress tested.
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| [70] |
Influence of salinity on the in vitro development of glomus intraradices and on the in vivo physiological and molecular responses of mycorrhizal lettuce plants [J]. |
| [71] |
Regulative effect of Arbuscular Mycorrhizal Fungi on water absorption and expression of aquaporin genes in tomato under salt stress [J].盐胁迫下丛枝菌根真菌对番茄吸水及水孔蛋白基因表达的调控 [J].
采用盆栽试验研究不同浓度（0.5%和1.0%）NaCl胁迫下接种丛枝菌根真菌Glomus mosseae-2 对番茄吸水特性的影响，并用realtime-PCR技术分析了根系中5个水孔蛋白基因（LePIP1，LePIP2，LeTRAMP，LeAQP2，LeTIP）的表达。结果表明：盐胁迫下接种丛枝菌根真菌能促进植株生长和对水分的吸收，显著提高叶片相对含水量、叶片水势及根系水导；丛枝菌根真菌和盐胁迫共同调控了5个水孔蛋白基因的表达；与未接菌株相比，接种植株LeAQP2基因表达上调，其余4个基因表达下调。LeAQP2基因在接菌株根中的过量表达与盐胁迫下丛枝菌根真菌提高番茄根系水导有关。
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| [72] |
Effect of Arbuscular Mycorrhizal Fungi on growth, mineral nutrition, antioxidant enzymes activity and fruit yield of tomato grown under salinity stress [J].
The purpose of this study was to investigate the mechanisms underlying alleviation of salt stress by arbuscular mycorrhizal fungi Glomus mosseae. Tomato (Lycopersicon esculentum L. cv. Zhongzha105) plants were cultivated in soil with 0, 50 and 100 mM NaCl. Mycorrhization alleviated salt induced reduction of root colonization, growth, leaf area, chlorophyll content, fruit fresh weight and fruit yield. The concentrations of P and K were higher in AM compared with nonAM plants grown under nonsaline and saline conditions. Na concentration was lower in AM than nonAM plants grown under nonsaline and saline conditions. AMF colonization was accompanied by an enhancement of activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in leaves of both salt-affected and control plants. In addition, inoculation with AMF caused reduction in MDA content in comparison to salinized plants, indicating lower oxidative damage in the colonized plants. In conclusion, AMF may protect plants against salinity by alleviating the salt induced oxidative stress.
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| [73] |
Effect of AM Fungi on salt resistance of maize [J].盐胁迫下接种AM真菌对玉米耐盐性的影响 [J].
以玉米品种陕单16号幼苗为材料,用盆栽法研究了不同含盐量（0、0.5、1.0、1.5和2.0 NaCl g/kg）土壤接种AM真菌（Glomus mosseae）对玉米幼苗生物量、盐害级数,以及叶片中电解质透出率、丙二醛、O·2-、H2O2含量和保护酶活性的影响.结果表明：在盐胁迫下,接种AM真菌增加了玉米植株生物量,降低了玉米的盐害级数;菌根植株叶片中过氧化氢酶的活性高于非菌根植株,而过氧化物酶、抗坏血酸氧化酶和多酚氧化酶的活性则为非菌根植株高于菌根植株;超氧化物歧化酶的活性在NaCl浓度为0、0.5和1.0 g/kg时为非菌根植株高于菌根植株,而在NaCl浓度为1.5和2.0 g/kg时则为菌根植株高于非菌根植株;菌根植株叶片中电解质透出率、丙二醛、O·2-和H2O2的含量低于非菌根植株.可见,AM真菌的侵染提高了玉米的耐盐性,缓解了由盐胁迫引起的过氧化胁迫对玉米植株的伤害,但这一缓解作用并不只是通过提高保护酶活性来实现的,可能还存在一些非酶促的调节机制.
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| [74] |
Effects of arbuscular mycorrhizal fungus on the growth and physiological salt tolerance parameters of Carthamus tinctorius seedlings under salt stress [J].丛枝菌根真菌对盐胁迫下红花幼苗生长及耐盐生理指标的影响 [J].
通过盆栽试验研究了NaCl胁迫下接种从枝菌根真菌(AMF)摩西球囊霉(Glomus mosseae)对红花(Carthamus tinctorius)生长及生理指标的影响.结果表明,接种摩西球囊霉能够显著提高了盐胁迫下红花地下部干重、地上部叶绿素含量,减少了丙二醛 (MDA)的积累量.在盐处理下,接种AMF较不接种显著增加了红花叶片游离脯氨酸和可溶性糖的含量,提高了红花的总抗氧化能力.此外,接种AMF还能增 强红花对矿质营养元素P、Mg的吸收.在高盐浓度(3‰)时,接菌较不接菌显著减少了红花对Na+的吸收,同时显著增加了红花叶片中K+的浓度.因此,摩 西球囊霉能减少盐对叶绿素合成的干扰作用,从而提高叶绿素含量;同时通过提高渗透调节物质含量、增强矿质元素的吸收、减小膜脂过氧化程度以及降低高盐浓度 时Na+的吸收来缓解红花的盐胁迫.
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| [75] |
Effects of strong light and active oxygen on photosynthesis in soybean [J].强光及活性氧对大豆光合作用的影响 [J]. |
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Effect of salinity stress on mycorrhizal association and growth response of peanut infected by Glomus mosseae [J].
Arbuscular mycorrhiza is a mutualistic association between fungi and higher plants, and play a critical role in nutrient cycling and stress tolerance. However, much less is known about the mycorrhiza-mediated enhancement in growth and salinity tolerance of the peanuts (Arachis hypogaea L.) growing in the arid and semi-arid areas. Therefore, mycorrhizal status of Glomus mosseae in diverse salinity levels on original substrate soil conditions was investigated. Different growth parameters, accumulation of proline content and salt stress tolerance were studied. These investigations indicated that the arbuscular mycorrhizal fungi could improve growth of peanuts under salinity through enhanced nutrient absorption and photosynthesis. Chlorophyll content and leaf water content were increased significantly under salinity stress by the inoculation with mycorrhizal fungi. Tolerance of the plants to salinity was increased and the mycorrhizal association was found highly effective in enhancing peanut growth and establishment in soils under salinity and deficient in phosphorus.
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| [77] |
Effects of salinity on photosynthetic physiology and chlorophyll fluorescence characteristics of Mulberry(Morus alba) seedlings [J].盐胁迫对桑树幼苗光合生理及叶绿素荧光特性的影响 [J].
试验以黄河流域和西北地区常用的桑树砧木-1年生实生桑树幼苗为试验材料，采用盆栽加盐的方 式模拟盐胁迫环境，通过设置1、3、5、7g·kg^-1等4个盐分梯度，以不加NaCI（0g·kg^-1）为对照（CK），研究NaCl胁迫对桑树幼 苗光合作用和叶绿素荧光特性的影响。结果表明：1g·kg^-1NaCl处理对桑树幼苗叶片的净光合速率（Pn）没有明显影响；而3、5、7g·kg^- 1等NaCl处理则对Pn具有明显的抑制作用，5、7g·kg^-1等的NaCl处理的影响显著，造成桑树幼苗Pn急剧降低，部分植株受害严重，甚至死 亡。此外，1、3g·kg^-1等NaCl处理对桑树幼苗的气孔导度（Gs）、蒸腾速率（Tr）、水分利用率（WUE）和胞间CO2浓度（Ci）没有明显 影响，而5、7g·kg^-1等NaCl处理则显著提高了桑树幼苗的Ci，降低了Gs、Tr和WUE。盐胁迫对桑树幼苗叶片的叶绿素荧光参数具有一定的影 响。随NaCl处理浓度增大，初始荧光（Fo）呈下降的趋势，而非光化学荧光淬灭系数（NPQ）则先升后降，但处理之间F0和NPQ变化差异不明显；1、 3g·kg^-1等NaCl处理对桑树幼苗的最大荧光（Fm）、最大光化学效率（Fv／Fm）、潜在光化学效率（Fv／Fo）和PSⅡ有效光化学量子效率 （ΦPSⅡ）没有明显影响，而5、7g·kg^-1等NaCl处理则显著降低其Fm、Fv／Fm、Fv／Fo和审ΦPSⅡ。
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| [78] |
Influence of arbuscular mycorrhizae on photosynthesis and water status of maize plants under salt stress [J]. |
| [79] |
Chlorophyll fluorescence and its progress in detecting water stress [J].叶绿素荧光及其在水分胁迫监测中的研究进展 [J]. |
| [80] |
Application of chlorophyll fluorescence dynamics to plant physiology in adverse circumstance [J].叶绿素荧光动力学在研究植物逆境生理中的应用 [J].
叶绿素荧光动力学技术被称为研究植物光合功能的快速、无损伤探针 ,已逐渐在研究环境胁迫对植物光合作用影响上进行利用 ,本文就这方面的研究工作及叶绿素荧光动力学基本理论作一综述
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| [81] |
Mycorrhizal infection ameliorates chlorophyll content and nutrient uptake of lettuce exposed to saline irrigation [J].
ABSTRACT Salinity is one of the most serious environmental problems influencing crop growth. Today, the use of microorga- nisms as biofertilizers in agriculture is quite diffused, and good results have been obtained in terms of induction of resistance to biotic and abiotic stresses in crops. The effects of inoculation with a mixture of the mycorrhizal fungi Glomus mosseae, G. intraradices and G. coronatum have been investigated on lettuce (Lactuca sativa L.) cultivated at three different levels of salinity of the irrigation water (0, 1.5 and 3 g NaCl/l) and collected during three subse- quent samplings. Dry mass production was significantly enhanced in the inoculated plants collected at the first sampling, and the effect was even more evident at the highest salinity; however, it was not observed at the latest samplings. The chlorophyll content and total foliar area were mostly enhanced by colonization with the mycorrhizal fungi. Moreover, mycorrhization significantly reduced Na and Cl plant uptake, and stimulated the absorption of K and P. The experiment suggests that mycorrhization can be a suitable way to induce salt-stress resistance in horti - cultural crops, and that it can show its best effects at medium-high salinity levels of the irrigation water.
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