scholarly journals Influence of drought and salt stress on the growth of young Populus nigra ‘Italica’ plants and associated mycorrhizal fungi and non-mycorrhizal fungal endophytes

New Forests ◽  
2021 ◽  
Author(s):  
Magdalena Kulczyk-Skrzeszewska ◽  
Barbara Kieliszewska-Rokicka

AbstractPopulus nigra ‘Italica’ (Lombardy poplar) is a breeding cultivar of black poplar, widely used as a street tree or windbreak, often exposed to salinity and limited water availability. Populus roots can develop dual mycorrhizal associations with ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi, and with non-mycorrhizal fungal endophytes (FE). The symbiotic fungi may alleviate the effects of adverse environmental conditions. We investigated the performance (growth and symbiotic associations) of one-year-old Populus nigra ‘Italica’ grown from woody cuttings in soil from natural poplar habitat and subjected to water scarcity and soil salinity (50 mM NaCl, 150 mM NaCl, 250 mM NaCl). With increasing soil salinity, a decrease in the growth parameters of the aboveground parts of the poplar plantlets and their fine roots were found; however, the roots were more resistant to the stress factors analyzed than the shoots. ECMF, AMF, and non-mycorrhizal FE were all tolerant to increased salt levels in the soil, and the ECM abundance was significantly higher under conditions of mild salinity (50 mM NaCl, 150 mM NaCl) compared to the control plants and those treated with 250 mM NaCl. Our results indicated that enhanced soil salinity increased the content of sodium and chlorine in leaves, but did not affect significantly the concentrations potassium, magnesium, calcium, phosphorus, or nitrogen. Significant accumulation of proline in leaves suggest salt stress of P. nigra ‘Italica’ treated with 250 mM NaCl and contribution of proline to the plant defense reactions.

Author(s):  
Hashem Abeer ◽  
E. F. Abd_Allah ◽  
A. A. Alqarawi ◽  
Dilfuza Egamberdieva

The aim of present study was to examine the effect of arbuscular mycorrhizal fungi (AMF) on the growth, lipid peroxidation, antioxidant enzyme activity and some key physio-biochemical attributes in cowpea (<italic>Vigna unguiculata</italic> [L.] Walp.) subjected to salt stress. Salt stress (200 mM NaCl) reduced growth, biomass, relative water content and chlorophyll pigment content in cowpea leaves. AMF ameliorated the negative impact of salinity on the growth parameters studied. The activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and glutathione reductase (GR) enhanced under salt stress and AMF inoculation further enhanced their activity, thus strengthening the plant’s defense system. Proline content increased in salt stressed plants as well as AMF-inoculated plants providing efficient protection against salt stress. Besides this AMF also increased uptake of mineral elements which have direct impact on the osmoregulation of the plants. The present study shows that AMF possesses the potential to enhance salt tolerance of cowpea.


2007 ◽  
Vol 85 (7) ◽  
pp. 644-651 ◽  
Author(s):  
Donna Glassop ◽  
Rosamond M. Godwin ◽  
Sally E. Smith ◽  
Frank W. Smith

The completed rice-genome sequence was screened with a known inorganic phosphate (Pi) transporter sequence to reveal a family of 13 Pi transporters. This family can be used for studies into Pi acquisition and translocation throughout the plant. Plants that form symbiotic associations with arbuscular mycorrhizal (AM) fungi are of particular interest with respect to Pi acquisition because of their ability to utilize both direct and fungal pathways of uptake. Localization of transcripts of two Pi transporters by real-time RT-PCR and in situ hybridization were conducted in rice subjected to low Pi, high Pi, and AM colonization. One Pi transporter, ORYsa;Pht1;13, was detected in rice roots under all growth conditions. ORYsa;Pht1;11 was only expressed in roots colonized by AM fungi. Antisense RNA probes of ORYsa;Pht1;11 localized to cortical cells containing arbuscules and hyphal coils, formed by Glomus intraradices Schenck and Smith and Scutellospora calospora (Nicolson and Gerdemann) Walker and Sanders, respectively. Localization of the ORYsa;Pht1;13 probes was similar to that observed for ORYsa;Pht1;11 in colonized rice roots. This research proposes that at least two rice Pi transporters are involved in acquiring Pi via AM fungi, emphasising the complexity of Pi acquisition in plants with access to two Pi uptake pathways.


2019 ◽  
Author(s):  
Yuta Sugiura ◽  
Rei Akiyama ◽  
Sachiko Tanaka ◽  
Koji Yano ◽  
Hiromu Kameoka ◽  
...  

AbstractArbuscular mycorrhizal (AM) fungi, forming symbiotic associations with land plants, are obligate symbionts that cannot complete their natural life cycle without a host. Recently, fatty acid auxotrophy of AM fungi is supported by studies showing that lipids synthesized by the host plants are transferred to the fungi and that the latter lack genes encoding cytosolic fatty acid synthases (1-7). Therefore, to establish an asymbiotic cultivation system for AM fungi, we tried to identify the fatty acids that could promote biomass production. To determine whether AM fungi can grow on medium supplied with fatty acids or lipids under asymbiotic conditions, we tested eight saturated or unsaturated fatty acids (C12–C18) and two β-monoacylglycerols. Only myristate (C14:0) led to an increase in biomass of Rhizophagus irregularis, inducing extensive hyphal growth and formation of infection-competent secondary spores. However, such spores were smaller than those generated symbiotically. Furthermore, we demonstrated that R. irregularis can take up fatty acids in its branched hyphae and use myristate as a carbon and energy source. Myristate also promoted the growth of Rhizophagus clarus and Gigaspora margarita. Finally, mixtures of myristate and palmitate accelerated fungal growth and induced a substantial change in fatty acid composition of triacylglycerol compared with single myristate application, although palmitate was not used as a carbon source for cell wall biosynthesis in this culture system. In conclusion, here we demonstrate that myristate boosts asymbiotic growth of AM fungi and can also serve as a carbon and energy source.Significance statementThe origins of arbuscular mycorrhizal (AM) fungi, which form symbiotic associations with land plants, date back over 460 million years ago. During evolution, these fungi acquired an obligate symbiotic lifestyle, and thus depend on their host for essential nutrients. In particular, fatty acids are regarded as crucial nutrients for the survival of AM fungi owing to the absence of genes involved in de novo fatty acid biosynthesis in the AM fungal genomes that have been sequenced so far. Here, we show that myristate initiates AM fungal growth under asymbiotic conditions. These findings will advance pure culture of AM fungi.


2018 ◽  
Vol 3 ◽  
pp. 1-12
Author(s):  
Okon G. Okon ◽  
J.E. Okon ◽  
G.D.O. Eneh

This study evaluated the influence of Arbuscular Mycorrhizal (Rhizophagus irregularis) fungi inoculation (M) on the growth ofCucurbita maximaand as a buffer against phytoextraction of selected heavy metals (HM) (Zn, Cu, Cr, Cd and Pb) from a soil contaminated with crude oil (C). The experiment was set up using four soil treatments, each with three replicates C+ M-, C+ M+, C-M+ and C-M- (control without oil and inoculum). The shoot length, petiole length, number of nodes, leaf area and percentage germination ofC. maximawere significantly (p=0.05) reduced in uninoculated crude oil treatment (C+ M-), unpolluted mycorrhizal inoculated treatments (C-M+) showed remarkable response in growth parameters above the control (C-M-), while the polluted and inoculated treatment (C+ M+) showed significant (p=0.05) increase in growth parameters when compared to the polluted uninoculated treatment (C+ M-). Heavy metals analysis revealed a significant (p=0.05) difference in the heavy metal accumulation ofC. maxima. The heavy metals analyzed in this study are present thus inC. maxima; Zn>Cu>Cr>Pb>Cd. Crude oil polluted uninoculated treatment (C+ M-) recorded the highest concentrations of heavy metals than crude oil polluted inoculated (R. irregularis) treatment (C+ M+). Mycorrhizal inoculated unpolluted treatment (C-M+) and unpolluted uninoculated treatment (C-M-) indicated the lowest heavy metal concentrations. Inoculation withR. irregularissignificantly (p=0.05) reduced heavy metals uptake byC. maximaas observed in this study. Also, the negative effect of crude oil on AMF root colonization ofC. maximabyR. irregulariswas observed in polluted and inoculated treatment. HM often accumulate in the top layer of soil, therefore, are available for uptake by plants via roots, which is a major entry point of HM that ultimately affects different physiological processes. AM fungi can impinge on the chemical properties of heavy metals in the soil, their absorption by the host plant, and their allocation to different plant parts, affecting plant growth and the bioremediation process, thus making the AM fungi a suitable buffer for mitigating heavy metal stress onC. maxima.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Li Wang ◽  
Jieting Wu ◽  
Fang Ma ◽  
Jixian Yang ◽  
Shiyang Li ◽  
...  

Within the rhizosphere, AM fungi are a sensitive variable to changes of botanic and environmental conditions, and they may interact with the biomass of plant and other microbes. During the vegetative period of thePhragmites australisgrowing in the Sun Island Wetland (SIW), the variations of AM fungi colonization were studied. Root samples of three hydrologic gradients generally showed AM fungi colonization, suggesting that AM fungi have the ability for adaptation to flooded habitats. There were direct and indirect hydrological related effects with respect to AM fungi biomass, which interacted simultaneously in the rhizosphere. Though water content in soil and reed growth parameters were both positively associated with AM fungi colonization, only the positive correlations between reed biomass parameters and the colonization could be expected, or both the host plant biomass and the AM fungi could be beneficial. The variations in response of host plant to the edaphic and hydrologic conditions may influence the effectiveness of the plant-mycorrhizal association. This study included a hydrologic component to better assess the role and distribution of AM fungi in wetland ecosystems. And because of that, the range of AM fungi was extended, since they actually showed a notable adaptability to hydrologic gradients.


Author(s):  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
Abdilaziz A. Alqarawi ◽  
Stephan Wirth ◽  
Dilfuza Egamberdieva

The present study was carried with the aim to demonstrate and examine the impact of arbuscular mycorrhizal fungi (AMF) on the growth, anti-oxidants metabolism and some key physio-biochemical attributes including the osmotic constituents in <italic>Lupinus termis</italic> exposed to salt stress. Salt stress (250 mM NaCl) reduced growth, AMF colonisation, relative water content and chlorophyll pigment content. However, AMF ameliorated the negative effect of salinity on these growth parameters. Salt stress increased the activities of key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD). Inoculation of AMF enhanced the activities of these enzymes and caused an increase in the accumulation of osmotic components resulting in the maintainence of tissue water content. Proline, glycine betaine and sugars increased with salinity stress and AMF inoculation. Plants subjected to salt stress showed considerable variations in the endogenous levels of growth hormones. Reduced lipid peroxidation and increased membrane stability in AMF inoculated plants and enhanced activity of anti-oxidants enzymes confers the role of AMF in assuaging the salt stress induced deleterious effects.


2011 ◽  
Vol 33 (No. 2) ◽  
pp. 70-76 ◽  
Author(s):  
A. A Murkute ◽  
S. Sharma ◽  
S. K Singh

Citrus is grouped under the salt sensitive crops. Mycorrhizal fungi, a symbiotic relationship between plant roots and beneficial fungi, are supposed to impart the stress tolerance in the host plants. The stress tolerance improved due to Arbuscular Mycorrhizal fungi (AM fungi) colonization can be attributed to enhanced mineral nutrition. In the present study the efforts are made to evaluate the effectiveness of AM fungi with two citrus genotypes under salt stress. Three-month-old seedlings of Karna Khatta (Citrus Karna) and Troyer Citrange (Poncirus trifoliata &times; Citrus sinensis) were inoculated with the indigenous soil based AM inocula (mixed strains). The salinity gradient was developed by frequent irrigation with NaCl (0, 50, 100, 150 mM w/v). The results indicated that all the physical parameters were affected with increasing salinity. The proline accumulation increased while the chlorophyll, calcium and magnesium contents decreased significantly with increasing salinity. In general, the decreased AM colonization did not show any significant effects under salt stress. &nbsp;


Author(s):  
Yanhong Wang ◽  
Minqiang Wang ◽  
Yan Li ◽  
Aiping Wu ◽  
Juying Huang

The study aimed to investigate the effects of colonization with two arbuscular mycorrhizal (AM) fungi, Funneliformis mosseae , Diversispora versiformis , alone and in combination on the growth and nutrient acquisition of NaCl-stressed Chrysanthemum morifolium (Hangbaiju) plants in the greenhouse experiment. Mycorrhizal and non-mycorrhizal Hangbaiju plants were grown under different salinity levels imposed by 0, 50 and 200 mM NaCl for five months, following 6 weeks of non-saline pre-treatment. The results showed that root length, shoot and root dry weight, total dry weight, shoot and root N concentration were higher in mycorrhizal than in non-mycorrhizal plants under moderate saline conditions especially with D. versiformis colonization. As salinity increased, the mycorrhizal colonization, the mycorrhizal dependence (MD) decreased. Enhancement of tissue N acquisition is probably the main mechanism underlying salt tolerance in AM plants. It is suggested that the symbiotic associations between D. versiformis fungus and C. morifolium plants may be taken as a biotechnological practice in culture.


2014 ◽  
Vol 6 (3) ◽  
pp. 381-393 ◽  
Author(s):  
Promita DATTA ◽  
Mohan Vinayak KULKARNI

Symbiotic association between arbuscular mycorrhizal (AM) species and host plant roots improves plant growth and protects them from several abiotic stress factors. In the present study, the effect of Glomus mosseae and Glomus fasciculatum as an individual inoculation and in combination was studied on two legumes (Glycine max and Cyamopsis tetragonoloba) under soil salinity stress gradient [1.04 (control) to 8.26 dS/m]. Individual and co-inoculation of both the AM fungi alleviated adverse salt effect, with improvement in plant dry weight matter and biochemical parameters. However, these two isolates worked better in combination with respect to higher accumulation of soluble carbohydrate, reducing sugar, protein, proline concentration etc. C. tetragonoloba showed better response as compared to G. max in relation to improvement in nutritional profile under salt stress after AM treatment. As compared to non-mycorrhizal counterparts, co-inoculation with G. mosseae and G. fasciculatum in C. tetragonoloba enhanced total chlorophyll (14.83% at soil salinity of 3.78 dS/m), soluble carbohydrate (17.26% at soil salinity of 5.94 dS/m), proline (8.79% at soil salinity of 3.78 dS/m) while exposed to different soil salinity levels. Also, co-colonization with both the isolates showed more root colonization (%) and may be responsible for the better effect in salt stress alleviation. Electrolyte leakage of mycorrhizal plants was lowered at soil salinity gradient of 2.10 to 8.26 dS/m and hence, maintained membrane stability. These two isolates can be utilized as bio-inoculant in alleviation of adverse salt effect in soil in association with the two test legume plants.


2020 ◽  
Vol 117 (41) ◽  
pp. 25779-25788
Author(s):  
Yuta Sugiura ◽  
Rei Akiyama ◽  
Sachiko Tanaka ◽  
Koji Yano ◽  
Hiromu Kameoka ◽  
...  

Arbuscular mycorrhizal (AM) fungi, forming symbiotic associations with land plants, are obligate symbionts that cannot complete their natural life cycle without a host. The fatty acid auxotrophy of AM fungi is supported by recent studies showing that lipids synthesized by the host plants are transferred to the fungi, and that the latter lack genes encoding cytosolic fatty acid synthases. Therefore, to establish an asymbiotic cultivation system for AM fungi, we tried to identify the fatty acids that could promote biomass production. To determine whether AM fungi can grow on medium supplied with fatty acids or lipids under asymbiotic conditions, we tested eight saturated or unsaturated fatty acids (C12 to C18) and two β-monoacylglycerols. Only myristate (C14:0) led to an increase in the biomass ofRhizophagus irregularis, inducing extensive hyphal growth and formation of infection-competent secondary spores. However, such spores were smaller than those generated symbiotically. Furthermore, we demonstrated thatR. irregulariscan take up fatty acids in its branched hyphae and use myristate as a carbon and energy source. Myristate also promoted the growth ofRhizophagus clarusandGigaspora margarita. Finally, mixtures of myristate and palmitate accelerated fungal growth and induced a substantial change in fatty acid composition of triacylglycerol compared with single myristate application, although palmitate was not used as a carbon source for cell wall biosynthesis in this culture system. Our findings demonstrate that myristate boosts the asymbiotic growth of AM fungi and can also serve as a carbon and energy source.


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