1.Minqin Salinization Research Station,Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China2.University of Chinese Academy of Sciences, Beijing 100049, China
引用本文: 潘晶, 黄翠华, 罗君, 彭飞, 薛娴. 盐胁迫对植物的影响及AMF提高植物耐盐性的机制[J]. 地球科学进展, 2018, 33(4): 361-372, doi:10.11867/j.issn.1001-8166.2018.04.0361
PanJing, HuangCuihua, LuoJun, PengFei, XueXian. Effects of Salt Stress on Plant and the Mechanism of Arbuscular Mycorrhizal Fungi Enhancing Salt Tolerance of Plants[J]. Advances in Earth Science, 2018, 33(4): 361-372, doi:10.11867/j.issn.1001-8166.2018.04.0361
Copyright 2018 地球科学进展 编辑部
First author:Pan Jing (1988-), female, Minqin County, Gansu Province, Ph. D student. Research areas include degraded land improvement.E-mail:firstname.lastname@example.org
Supported Project supported by the Program of Domestic Cooperation for Chinese Academy of Sciences “Experimental study and demonstration on the use of Lycium ruthenicum/Saline-alkali soil”(No.43800312-6); The National Key Research and Development Program of China “Key techniques and demonstration of desertification on control in semiarid area in North China”(No.2016YFC0500909).;
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.
Arbuscular Mycorrhizal Fungi
图21001-8166-33-4-361/img_2.jpg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
Fig.21001-8166-33-4-361/img_2.jpg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
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
Ruizlozano JM, PorcelR, AzcónC, et al. Regulation by arbuscular mycorrhizae of the integrated physiological response to salinity in plants: New challenges in physiological and molecular studies[J]. , 2012, 63(11): 4 033-4 044.
Excessive salt accumulation in soils is a major ecological and agronomical problem, in particular in arid and semi-arid areas. Excessive soil salinity affects the establishment, development, and growth of plants, resulting in important losses in productivity. Plants have evolved biochemical and molecular mechanisms that may act in a concerted manner and constitute the integrated physiological response to soil salinity. These include the synthesis and accumulation of compatible solutes to avoid cell dehydration and maintain root water uptake, the regulation of ion homeostasis to control ion uptake by roots, compartmentation and transport into shoots, the fine regulation of water uptake and distribution to plant tissues by the action of aquaporins, the reduction of oxidative damage through improved antioxidant capacity and the maintenance of photosynthesis at values adequate for plant growth. Arbuscular mycorrhizal (AM) symbiosis can help the host plants to cope with the detrimental effects of high soil salinity. There is evidence that AM symbiosis affects and regulates several of the above mentioned mechanisms, but the molecular bases of such effects are almost completely unknown. This review summarizes current knowledge about the effects of AM symbiosis on these physiological mechanisms, emphasizing new perspectives and challenges in physiological and molecular studies on salt-stress alleviation by AM symbiosis.
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.
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.
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.
EvelinH, KapoorP, GiriB.Arbuscular mycorrhizal fungi in alleviation of salt stress: A review[J]. , 2009, 104(7): 1 263-1 280.
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.
[郭敏, 王楠, 付畅. 植物根系耐盐机制的研究进展[J]. , 2012,(6): 7-12.]
GuoMin, WangNan, FuChang.Progress of studies on salt tolerance mechanisms in plant root system under salt stress[J]., 2012,(6): 7-12.
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.
Zhu JK.Plant salt tolerance[J]. , 2001, 6(2): 66-71.
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.
GiriB, MukerjiK.Mycorrhizal inoculant alleviates salt stress in Sesbania aegyptiaca and Sesbania grandiflora under field conditions: Evidence for reduced sodium and improved magnesium uptake[J]. , 2004, 14(5): 307-312.
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.
Hammer EC, NasrH, PallonJ, et al. Elemental composition of arbuscular mycorrhizal fungi at high salinity[J]. , 2011, 21(2): 117-129.
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.
CaoYanpo, DaiPeng, DaiSuying, et al. Effects of Arbuscular Mycorrhizal Fungi(AMF)on seedling growth and Na+、K+、Ca2+、Mg2+ contents and distribution in asparagus under salt stress[J]. , 2015, 34(6):1 699-1 704.
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.
AshrafM.Some important physiological selection criteria for salt tolerance in plants[J]., 2004, 199(5): 361-376.
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.
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.
PorcelR, ArocaR, Ruiz-Lozano J M. Salinity stress alleviation using arbuscular mycorrhizal fungi: A review[J]., 2012, 32(1): 181-200.
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.
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.
[李涛. AM真菌对不同盐生植物抗盐性的影响[D]., 2009.]
LiTao.Effects of AM Fungi on Salt Resistance of Different Types of Halophytes[D]. , 2009.
Cantrell IC, Linderman RG.Preinoculation of lettuce and onion with VA mycorrhizal fungi reduces deleterious effects of soil salinity[J]., 2001, 233(2): 269-281.
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.
HeZ, HuangZ.Expression analysis of LeNHX1 gene in mycorrhizal tomato under salt stress[J]., 2013, 51(1): 100-104.
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.
OuziadF, WildeP, SchmelzerE, et al. Analysis of expression of aquaporins and Na+/H+, transporters in tomato colonized by arbuscular mycorrhizal fungi and affected by salt stress[J]. , 2006, 57(1/2): 177-186.
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.
Asghari H R.Vesicular-Arbuscular (VA) mycorrhizae improve salinity tolerance in pre-inoculation subterranean clover (Trifolium subterraneum) seedlings[J]. , 2012, 2(3): 243-256.
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.
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...
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
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.
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.
Wu QS, Zou YN, He XH, et al. Arbuscular mycorrhizal fungi can alter some root characters and physiological status in trifoliate orange (Poncirus trifoliata, L. Raf.) seedlings[J]., 2011, 65(2): 273-278.
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.
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...
GargN, ManchandaG.Role of Arbuscular Mycorrhizae in the Alleviation of Ionic, Osmotic and Oxidative Stresses Induced by Salinity in Cajanus cajan(L.) Millsp. (pigeonpea)[J]., 2009, 195(2): 110-123.
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.
KumarA, SharmaS, MishraS.Influence of Arbuscular Mycorrhizal (AM) fungi and salinity on seedling growth, solute accumulation, and mycorrhizal dependency of Jatropha curcas L.[J]., 2010, 29(3): 297-306.
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.
Wu QS, Zou YN, LiuW, et al. Alleviation of salt stress in citrus seedlings inoculated with mycorrhiza: Changes in leaf antioxidant defense systems[J]., 2010, 56(10): 470-475.
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...
HanBing, HeChaoxing, GuoShirong, et al. Effects of arbuscular mycorrhizal fungi on osmoregulation substance contents and antioxidant enzyme activities of cucumber seedlings under salt stress[J]., 2011, 31(12):2 492-2 497.
Sannazzaro AI, EcheverríaM, Albertó EO, et al. Modulation of polyamine balance in Lotus glaber by salinity and arbuscular mycorrhiza[J]., 2007, 45(1): 39-46.
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.
Alqarawi AA, Allah E F A, Hashem A. Alleviation of salt-induced adverse impact via mycorrhizal fungi in Ephedra aphylla Forssk[J]., 2014, 9(9): 802-810.
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.
Santa-CruzA, AcostaM, RusA, et al. Short-term salt tolerance mechanisms in differentially salt tolerant tomato species[J]., 1999, 37(1): 65-71.
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.
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.
Ruiz-Lozano JM, ArocaR. Modulation of Aquaporin Genes by the Arbuscular Mycorrhizal Symbiosis in Relation to Osmotic Stress Tolerance[M]. , 2010.
ArocaR, PorcelR, Ruiz-Lozano J M. How does arbuscular mycorrhizal symbiosis regulate root hydraulic properties and plasma membrane aquaporins in Phaseolus vulgaris, under drought, cold or salinity stresses?[J]. , 2007, 173(4): 808-816.
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.
JahromiF, ArocaR, PorcelR, et al. 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]. , 2008, 55(1): 45-53.
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.
XuYao, FanYan, YuYunhe, et al. Effects of arbuscular mycorrhizal fungus on the growth and physiological salt tolerance parameters of Carthamus tinctorius seedlings under salt stress[J]. , 2014, 33(12):3 395-3 402.
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.
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.