Stress Tolerance In Soybean Research Articles

GA3 and BAP phytohormone seed priming enhances germination and PEG induced drought stress tolerance in soybean by triggering the expression of osmolytes, antioxidant enzymes and related genes at the early seedling growth stages

Drought stress strongly affects seed germination and seedling development during the early stages of plant growth in soybean (Glycine max L.). Seed priming with phytohormone (PH) is known to regulate various physiological and biochemical processes that govern plant growth and yield under optimal and stress conditions. In the present study, the effects of seed priming with Gibberellic acid (GA3) (0.28 mM), 6-Benzyl aminopurine (BAP) (20 mM) and Methyl Jasmonate (MJ) (2.5 mM) was studied during germination and at early seedling growth stages in JS-335 (drought sensitive) and MAUS-71 (moderately drought tolerant) soybean varieties under PFG induced drought stress conditions. The seed priming effects were studied in terms of germination percentage and rate (Timson Index), accumulation of osmolytes (proline and glycine betaine), antioxidant enzymes activity (superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT)), and the relative expression of genes viz., Cu/Zn-superoxide dismutase copper chaperone (SOD-CCS) , iron-superoxide dismutase (SODB2) , betaine aldehyde dehydrogenase (BADH2) and dehydration-responsive element binding protein (DREB2A). The germination percentage of non-primed soybean seeds decreased under drought stress but significantly increased upon GA3 and BAP priming. Interestingly, seed priming with MJ completely inhibited the germination in both the varieties. GA3 and BAP seed priming increased proline and glycine betaine accumulation under PEG induced drought stress in both the soybean varieties. The results showed that the activities of SOD, APX and CAT were significantly enhanced in the leaves of seedlings raised from GA3 and BAP-primed seeds, as compared to the non-primed seeds under the drought stress conditions. Isozyme profiling of SOD and APX revealed that the GA3 and BAP seed priming treatments enhanced the drought-inducible expression of SOD isozymes rather than inducing novel isoforms. In case of APX isozymes, GA3 seed priming appears to preserve APX isozyme diversity in both varieties, and BAP seed priming elevated the expression of APX isoforms in both soybean varieties under the drought conditions. In response to the drought stress, relative expression of the genes associated with superoxide dismutase and glycine betaine viz., SOD CCS, SODB2, BADH2 and DREB2A was markedly upregulated in the leaves of seedlings raised from the GA3 and BAP primed seeds in both the soybean varieties. The global correlation analysis designated that the osmolyte Proline, antioxidant enzyme APX and CAT, and SOD CCS, SODB2, BADH2 and DREB2A genes were potent regulator for drought stress tolerance mechanism in soybean. This study illuminates the intricate interplay of GA3 and BAP hormonal seed priming during the germination and early seedling stages in soybean plants under the drought stress. This finding emphasizes the critical consideration of genotype specific reactions to the hormonal seed priming under PEG induced drought stress conditions.

Retraction: The intervention of classical and molecular breeding approaches to enhance flooding stress tolerance in soybean - An review.

[This retracts the article DOI: 10.3389/fpls.2022.1085368.].

In-silico identification and characterization of sucrose transporter genes and their differential expression pattern under salinity stress in Glycine max

Plant sucrose transporters, involved in sugar transport, are key in facilitating sugar flux across the plant cell membranes. However, external stress stimuli significantly impact these sucrose transporters (SWEET/MST/SUT) and, ultimately, the distribution of photosynthates. This has importance as sucrose is a prime energy source, a signaling molecule, and an osmolyte playing a key role in growth and development processes. This study aims to identify and comprehensive in silico characterization and involvement of soybean sucrose transporters GlymaSWEET, GlymaMST, and GlymaSUT in plant development and salt stress responses in an important oilseed crop soybean (Glycine max L.). A genome-wide screening of soybean revealed 13 GlymaSWEET, 6 GlymaMST, and 5 GlymaSUT orthologues as confirmed from the eggNOG database. Probable sites of these proteins were found to be the membranes of cells and organelles, as suggested by their sub-cellular localization. The cis-regulatory elements of these transporters’ promoters indicated their involvement in environmental stress responses. MicroRNA interactions with these transporters were also studied, besides 3-D protein structure prediction using in silico approaches. To gain an insight into the functional divergence of GlymaSWEET, GlymaMST, and GlymaSUT transporters, qRT-PCR-based gene expression analysis was done both in control and salt-treated root and leaf tissues of two contrasting Indian soybean varieties MAUS-47 (salt-tolerant) and Gujosoya-2 (salt-sensitive). Differential gene expression was observed with varying degrees amongst the varieties and the treatments. Overall, we can conclude that the identified GlymaSWEET, GlymaMST, and GlymaSUT have the potential to be explored as candidate genes for engineering salinity stress tolerance in soybean and other plants.

Phytohormonal modulation of the drought stress in soybean: outlook, research progress, and cross-talk.

Phytohormones play vital roles in stress modulation and enhancing the growth of plants. They interact with one another to produce programmed signaling responses by regulating gene expression. Environmental stress, including drought stress, hampers food and energy security. Drought is abiotic stress that negatively affects the productivity of the crops. Abscisic acid (ABA) acts as a prime controller during an acute transient response that leads to stomatal closure. Under long-term stress conditions, ABA interacts with other hormones, such as jasmonic acid (JA), gibberellins (GAs), salicylic acid (SA), and brassinosteroids (BRs), to promote stomatal closure by regulating genetic expression. Regarding antagonistic approaches, cytokinins (CK) and auxins (IAA) regulate stomatal opening. Exogenous application of phytohormone enhances drought stress tolerance in soybean. Thus, phytohormone-producing microbes have received considerable attention from researchers owing to their ability to enhance drought-stress tolerance and regulate biological processes in plants. The present study was conducted to summarize the role of phytohormones (exogenous and endogenous) and their corresponding microbes in drought stress tolerance in model plant soybean. A total of n=137 relevant studies were collected and reviewed using different research databases.

Enhancement of osmotic stress tolerance in soybean seed germination by bacterial bioactive extracts.

Soybean (Glycine max (L.) Merr.) is important to the global food industry; however, its productivity is affected by abiotic stresses such as osmosis, flooding, heat, and cold. Here, we evaluated the bioactive extracts of two biostimulant bacterial strains, Bacillus butanolivorans KJ40 and B. siamensis H30-3, for their ability to convey tolerance to osmotic stress in soybean seeds during germination. Soybean seeds were dip-treated in extracts of KJ40 (KJ40E) or H30-3 (H30-3E) and incubated with either 0% or 20% polyethylene glycol 6000 (PEG), simulating drought-induced osmotic stress. We measured malondialdehyde content as a marker for lipid peroxidation, as well as the activity of antioxidant enzymes, including catalase, glutathione peroxidase, and glutathione reductase, together with changes in sugars content. We also monitored the expression of genes involved in the gibberellic acid (GA)-biosynthesis pathway, and abscisic acid (ABA) signaling. Following osmotic stress in the extract-treated seeds, malondialdehyde content decreased, while antioxidant enzyme activity increased. Similarly, the expression of GA-synthesis genes, including GmGA2ox1 and GmGA3 were upregulated in KJ40E-dipped seeds at 12 or 6 h after treatment, respectively. The ABA signaling genes GmABI4 and GmDREB1 were upregulated in H30-3E- and KJ40E-treated seeds at 0 and 12 h after treatment under osmotic stress; however, GmABI5, GmABI4, and GmDREB1 levels were also elevated in the dip-treated seeds in baseline conditions. The GA/ABA ratio increased only in KJ40E-treated seeds undergoing osmotic stress, while glucose content significantly decreased in H30-3E-treated seeds at 24 h after treatment. Collectively, our findings indicated that dip-treatment of soybean seeds in KJ40E and H30-3E can enhance the seeds' resistance to osmotic stress during germination, and ameliorate cellular damage caused by secondary oxidative stress. This seed treatment can be used agriculturally to promote germination under drought stress and lead to increase crop yield and quality.

GmPARPs differentially regulate the drought and heat stress tolerance in soybean

GmPARPs differentially regulate the drought and heat stress tolerance in soybean

Enhancing Biotic Stress Tolerance in Soybean Affected by Rhizoctonia solani Root Rot Through an Integrated Approach of Biocontrol Agent and Fungicide.

Rhizoctonia solani causes root rot in soybean, a worldwide severe concern for soybean cultivation. The fungus grows and clogs the xylem tissue of the host plant by producing numerous sclerotia, which results in disease symptoms, such as yellowing of leaves, wilt, and plant death. Overuse of chemical fungicides increases the threat of developing resistance to pathogens, reduces soil productivity, and negatively impacts the health of the soil, the environment, and humans. An integrated pest management strategy improves crop yield, profit, and safety. The present study focused on a fungicide (carbendazim) compatibility test with a biocontrol agent (Pseudomonas fluorescence). It evaluated the effect of this combined approach on photosynthetic reactions and growth in soybean in the presence of the fungal pathogen R. solani. The study showed that P. fluorescence significantly inhibited the mycelial growth of R. solani (43%) and tolerated 0.05-0.15% concentration of carbendazim. This confirms the suitability compatibility of P. fluorescence with chemical fungicides for IPM. These novel blending significantly reduced the disease incidence by about 75%, and a 72% decrease in disease severity was observed compared to pathogen control. Moreover, this combined approach has also improved plant growth, yield parameters, and photosynthetic efficiency in the presence of R. solani treated with an integrated system showed better overall growth despite being infected by the pathogen.

Deciphering the myth of cold tolerance in soybean: An overview of molecular breeding applications

The soybean is a source of several dietary components, including milk, protein, and oil. Cold stress has significantly curtailed soybean growth and yield in large areas and caused a high risk to global food security. The main objective of soybean breeders is to improve soybean resistance to cold stress. Conventional breeding approaches have made significant progress in developing cold tolerance in soybean; however, the high cost and complex genetic mechanism of cold tolerance hindered the large scale of these techniques. Molecular tools like quantitative trait loci (QTL), genome-wide association studies (GWAS), transcription factors (TFs), genetic engineering, and transcriptome have been used to identify cold tolerant genes/QTL and to develop soybean cultivars tolerant to cold stress. Clustered, regularly interspaced short palindromic repeats (CRISPR/Cas9) is used to increase the abiotic stress tolerance in soybean; however, its use to edit the cold tolerance genes in soybean is limited. Mapping of QTL has accelerated the master-assisted selection (MAS) in soybean. This review presents a detailed overview of molecular techniques and their use in developing cold-tolerant soybean cultivars. Using CRISPR/Cas9 would increase the speed of molecular breeding for cold tolerance in soybean. This information will assist soybean researchers in uncovering the basis of cold stress tolerance in soybean and adopting the most suitable way to breed the cold tolerant cultivars which can thrive under the extreme pressure of cold stress.

Overexpression of soybean GmNAC19 and GmGRAB1 enhances root growth and water-deficit stress tolerance in soybean.

Soybean (Glycine max) is an important crop in agricultural production where water shortage limits yields in soybean. Root system plays important roles in water-limited environments, but the underlying mechanisms are largely unknown. In our previous study, we produced a RNA-seq dataset generated from roots of soybean at three different growth stages (20-, 30-, and 44-day-old plants). In the present study, we performed a transcriptome analysis of the RNA-seq data to select candidate genes with probable association with root growth and development. Candidate genes were functionally examined in soybean by overexpression of individual genes using intact soybean composite plants with transgenic hairy roots. Root growth and biomass in the transgenic composite plants were significantly increased by overexpression of the GmNAC19 and GmGRAB1 transcriptional factors, showing up to 1.8-fold increase in root length and/or 1.7-fold increase in root fresh/dry weight. Furthermore, greenhouse-grown transgenic composite plants had significantly higher seed yield by about 2-fold than control plants. Expression profiling in different developmental stages and tissues showed that GmNAC19 and GmGRAB1 were most highly expressed in roots, displaying a distinct root-preferential expression. Moreover, we found that under water-deficit conditions, overexpression of GmNAC19 enhanced water stress tolerance in transgenic composite plants. Taken together, these results provide further insights into the agricultural potential of these genes for development of soybean cultivars with improved root growth and enhanced tolerance to water-deficit conditions.

Modulation of the antioxidant system and primary metabolism confers aluminum stress tolerance in soybean

Modulation of the antioxidant system and primary metabolism confers aluminum stress tolerance in soybean

Zinc-finger protein GmZF351 improves both salt and drought stress tolerance in soybean.

Abiotic stress is one of the most important factors reducing soybean yield. It is essential to identify regulatory factors contributing to stress responses. A previous study found that the tandem CCCH zinc-finger protein GmZF351 is an oil level regulator. In this study, we discovered that the GmZF351 gene is induced by stress and that the overexpression of GmZF351 confers stress tolerance to transgenic soybean. GmZF351 directly regulates the expression of GmCIPK9 and GmSnRK, leading to stomata closing, by binding to their promoter regions, which carry two CT(G/C)(T/A)AA elements. Stress induction of GmZF351 is mediated through reduction in the H3K27me3 level at the GmZF351 locus. Two JMJ30-demethylase-like genes, GmJMJ30-1 and GmJMJ30-2, are involved in this demethylation process. Overexpression of GmJMJ30-1/2 in transgenic hairy roots enhances GmZF351 expression mediated by histone demethylation and confers stress tolerance to soybean. Yield-related agronomic traits were evaluated in stable GmZF351-transgenic plants under mild drought stress conditions. Our study reveals a new mode of GmJMJ30-GmZF351 action in stress tolerance, in addition to that of GmZF351 in oil accumulation. Manipulation of the components in this pathway is expected to improve soybean traits and adaptation under unfavorable environments.

Double the action: multimodal action of a CONSTANS-LIKE protein enhances stress tolerance in soybean.

Double the action: multimodal action of a CONSTANS-LIKE protein enhances stress tolerance in soybean.

The intervention of classical and molecular breeding approaches to enhance flooding stress tolerance in soybean - An review.

Abiotic stresses and climate changes cause severe loss of yield and quality of crops and reduce the production area worldwide. Flooding stress curtails soybean growth, yield, and quality and ultimately threatens the global food supply chain. Flooding tolerance is a multigenic trait. Tremendous research in molecular breeding explored the potential genomic regions governing flood tolerance in soybean. The most robust way to develop flooding tolerance in soybean is by using molecular methods, including quantitative trait loci (QTL) mapping, identification of transcriptomes, transcription factor analysis, CRISPR/Cas9, and to some extent, genome-wide association studies (GWAS), and multi-omics techniques. These powerful molecular tools have deepened our knowledge about the molecular mechanism of flooding stress tolerance. Besides all this, using conventional breeding methods (hybridization, introduction, and backcrossing) and other agronomic practices is also helpful in combating the rising flooding threats to the soybean crop. The current review aims to summarize recent advancements in breeding flood-tolerant soybean, mainly by using molecular and conventional tools and their prospects. This updated picture will be a treasure trove for future researchers to comprehend the foundation of flooding tolerance in soybean and cover the given research gaps to develop tolerant soybean cultivars able to sustain growth under extreme climatic changes.

Improvement of heat stress tolerance in soybean (Glycine max L), by using conventional and molecular tools.

The soybean is a significant legume crop, providing several vital dietary components. Extreme heat stress negatively affects soybean yield and quality, especially at the germination stage. Continuous change in climatic conditions is threatening the global food supply and food security. Therefore, it is a critical need of time to develop heat-tolerant soybean genotypes. Different molecular techniques have been developed to improve heat stress tolerance in soybean, but until now complete genetic mechanism of soybean is not fully understood. Various molecular methods, like quantitative trait loci (QTL) mapping, genetic engineering, transcription factors (TFs), transcriptome, and clustered regularly interspaced short palindromic repeats (CRISPR), are employed to incorporate heat tolerance in soybean under the extreme conditions of heat stress. These molecular techniques have significantly improved heat stress tolerance in soybean. Besides this, we can also use specific classical breeding approaches and different hormones to reduce the harmful consequences of heat waves on soybean. In future, integrated use of these molecular tools would bring significant results in developing heat tolerance in soybean. In the current review, we have presented a detailed overview of the improvement of heat tolerance in soybean and highlighted future prospective. Further studies are required to investigate different genetic factors governing the heat stress response in soybean. This information would be helpful for future studies focusing on improving heat tolerance in soybean.

Insight into the Mechanism of Salt-Induced Oxidative Stress Tolerance in Soybean by the Application of Bacillus subtilis: Coordinated Actions of Osmoregulation, Ion Homeostasis, Antioxidant Defense, and Methylglyoxal Detoxification.

Considering the growth-promoting potential and other regulatory roles of bacteria, we investigated the possible mechanism of the role of Bacillus subtilis in conferring salt tolerance in soybean. Soybean (Glycine max cv. BARI Soybean-5) seeds were inoculated with B. subtilis, either through a presoaking with seeds or a direct application with pot soil. After 20 days of sowing, both the seed- and soil-inoculated plants were exposed to 50, 100, and 150 mM of NaCl for 30 days. A clear sign of oxidative stress was evident through a remarkable increase in lipid peroxidation, hydrogen peroxide, methylglyoxal, and electrolyte leakage in the salt treated plants. Moreover, the efficiency of the ascorbate (AsA)–glutathione (GSH) pathways was declined. Consequently, the plant growth, biomass accumulation, water relations, and content of the photosynthetic pigments were decreased. Salt stress also caused an increased Na+/K+ ratio and decreased Ca2+. On the contrary, the B. subtilis inoculated plants showed increased levels of AsA and GSH, their redox balance, and the activities of the AsA–GSH pathway enzymes, superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, and peroxidase. The B. subtilis inoculated plants also enhanced the activities of glyoxalase enzymes, which mitigated methylglyoxal toxicity in coordination with ROS homeostasis. Besides this, the accumulation of K+ and Ca2+ was increased to maintain the ion homeostasis in the B. subtilis inoculated plants under salinity. Furthermore, the plant water status was uplifted in the salt treated soybean plants with B. subtilis inoculation. This investigation reveals the potential of B. subtilis in mitigating salt-induced oxidative stress in soybean plants through modulating the antioxidant defense and glyoxalase systems along with maintaining ion homeostasis and osmotic adjustments. In addition, it was evident that the soil inoculation performed better than the seed inoculation in mitigating salt-induced oxidative damages in soybean.

Associations of direct and indirect selection for pregermination anaerobic stress tolerance in soybean (Glycine max)

AbstractA set of diverse soybean genotypes were evaluated to identify contrasting phenotypes for understanding the genetics of waterlogging and response to the selection of primary and discernable traits for pregermination anaerobic stress tolerance. Agro‐morphological characterization of genotypes was also carried out. Screening and tolerance to waterlogging were based on the ability of genotypes to germinate in excessive stress duration in days. The existence of significant variability in genotypes of soybean suggested the use of systematic selection for improving pregermination anaerobic stress tolerance. The study revealed that waterlogging tolerance was governed by testa colour of genotypes. Our results indicated a significant (P < 0.05) correlation with seed weight, flower, hypocotyl and testa colour under pregermination anaerobic stress. In conclusion, the study points out that testa integrity and delay in germination are required to be used as one of the criteria for indirect selection in breeding for pregermination waterlogging tolerance.

Functional characterization of transcription factor WIN1 genes associated with lipid biosynthesis and stress tolerance in soybean (Glycine max)

Transcription factor WAX INDUCER1 (WIN1) plays an important role in wax and cutin biosynthesis in plants. In this study, six GmWIN1 genes were identified from soybean ( Glycine max ), with GmWIN1–5 having high expression in flowers and seeds, particularly under cold stress. GmWIN1–5′s functions in lipid/oil biosynthesis and stress tolerance were characterized by its overexpression in soybean hairy roots and tobacco ( Nicotiana benthamiana ) plants. Under cold stress, GmWIN1–5 overexpression ( GmWIN1–5- OE) resulted in large oil enhancement and high level of phospholipids involved in cell membranes formation. Malondialdehyde content and elcetronlyte leakage in GmWIN1–5-OE plants was smaller than that in the wild-type control under cold stress, indicating that GmWIN1–5 promote plant stress tolerance. Moreover, GmWIN1–5-OE also led to upregulated expression of numerous genes involved in de novo fatty acid biosynthesis and triacylglycerol (TAG) production, including genes encoding phospholipase D ( PLD ), biotin carboxyl carrier protein 1 ( BCCP1 ), lysophosphatidic acid acyltransferase 5 ( LPAT5 ), and diacylglycerol acyltransferase 2 ( DGAT2 ). GmWIN1–5 directly bound to the promoter region of PLD gene. Overall, the results revealed that GmWIN1–5 can upregulate the biosynthesis and accumulation of lipids/oils, especially unsaturated fatty acids and phospholipids benefiting membrane integrity, and ultimately confer plants with high stress tolerance. • Six GmWIN1 members with structural integrity are identified in soybean ( Glycine max ). • Of the six GmWIN1s, GmWIN1-5 expression level was the highest in flower and seed tissues. • Overexpression of GmWiN1-5 in soybean hair roots increased total lipids and cold stress tolerance. • Ectopic expression of GmWIN1-5 in tobacco plant boosted oil content and stress tolerance. • GmWIN1-5 promoted expression of several lipid synthesis-related genes, particularly PLD.

Modulation of GmFAD3 expression alters abiotic stress responses in soybean.

This study focused on enhancing resilience of soybean crops to drought and salinity stresses by overexpression of GmFAD3A gene, which plays an important role in modulating membrane fluidity and ultimately influence plants response to various abiotic stresses. Fatty acid desaturases (FADs) are a class of enzymes that mediate desaturation of fatty acids by introducing double bonds. They play an important role in modulating membrane fluidity in response to various abiotic stresses. However, a comprehensive analysis of GmFAD3 in drought and salinity stress tolerance in soybean is lacking. We used bean pod mottle virus (BPMV)-based vector for achieving rapid and efficient overexpression as well as silencing of Omega-3 Fatty Acid Desaturase gene from Glycine max (GmFAD3) to assess the functional role of GmFAD3 in abiotic stress responses in soybean. Higher levels of recombinant BPMV-GmFAD3A transcripts were detected in overexpressing soybean plants. Overexpression of GmFAD3A in soybean resulted in increased levels of jasmonic acid and higher expression of GmWRKY54 as compared to mock-inoculated, vector-infected and FAD3-silenced soybean plants under drought and salinity stress conditions. The GmFAD3A-overexpressing plants showed higher levels of chlorophyll content, efficient photosystem-II, relative water content, transpiration rate, stomatal conductance, proline content and also cooler canopy under drought and salinity stress conditions as compared to mock-inoculated, vector-infected and FAD3-silenced soybean plants. Results from the current study revealed that GmFAD3A-overexpressing soybean plants exhibited tolerance to drought and salinity stresses. However, soybean plants silenced for GmFAD3 were vulnerable to drought and salinity stresses.

The non-specific lipid transfer protein GmLtpI.3 is involved in drought and salt tolerance in soybean

Plant non-specific lipid transfer proteins (nsLTPs/LTPs) play important roles in plant growth, development and abiotic stress responses. However, little is known about LTPs in soybean. In this study, 131 LTPs were identified and divided into ten types (I, II, III, IV, V, VI, VII, VIII, IX, and Y), and each GmLtp has the characteristic eight-cysteine motif (8 CM) of plant LTPs. RNA-seq data showed that most GmLtps responded to a variety of abiotic stresses. Among the GmLtp members, GmLtpⅠ.3 was significantly induced under drought and salt treatments. Overexpressing GmLtpⅠ.3 improved tolerance to drought and salt stresses in transgenic Arabidopsis and soybean. The results showed that the accumulation of reactive oxygen species (ROS) in the roots of GmLtpⅠ.3 -overexpressing (OE -GmLtpⅠ.3 ) plants decreased significantly, compare with GmLtpⅠ.3 RNA interference (RNAi- GmLtpⅠ.3 ) and empty vector (EV-Control) plants. Furthermore, compared with EV-Control, the expression level of GmSOD1 and GmSOD2 increased in OE- GmLtpI.3 . Contrarily, the expression of GmRBOHA and GmRBOHB decreased in OE- GmLtpI.3 . The results of this study provide the basis for further comprehensive analyses of LTP genes and insights into abiotic stress response mechanisms in soybean. • 131 plant non-specific lipid transfer proteins genes were identified and analyzed in soybean. • Overexpression of GmLtpⅠ.3 can improve Arabidopsis and soybean stress tolerance. • GmLtpⅠ.3 regulates soybean tolerance to drought and salt stresses at the molecular levels.

Dual inoculation with rhizobia and arbuscular mycorrhizal fungus improves water stress tolerance and productivity in soybean

A glasshouse experiment was conducted to understand the influence of rhizobia, Bradyrhizobium liaoningense and an arbuscular mycorrhizal fungus, Ambispora leptoticha on growth and yield performance of soybean cultivars, MAUS 2 and MAUS 212 (drought susceptible) and DSR 12 (drought tolerant) under different levels of moisture stress conditions. Three different water levels [100%, 75% and 50% FC] with three microbial inocula (B. liaoningense, A. leptoticha and B. liaoningense + A. leptoticha) served as main treatments and the water level treatments were imposed 31–45 days after sowing. Various growth, physiological and microbial parameters were recorded besides analysing the samples for nutrients. The results showed that the plant growth parameters like biovolume index, total dry biomass, root volume and seed yield were significantly higher in dual inoculated plants in all the cultivars at all the moisture levels. There was an increase in mean seed weight by 88% and dry biomass by 58% in dual inoculated plants compared to uninoculated plants. Further physiological parameters and nutrients level improved significantly with dual inoculation under stress condition. However significant difference in recorded parameters was not observed in plants grown at 100% and 75% FC suggesting dual inoculation of B. liaoningense + A. leptoticha is beneficial when stress is severe in all the 3 cultivars. The microbial and nutrient parameters followed the same trend. Further of the two drought susceptible cultivars, MAUS 2 performed better compared to MAUS 212 in all the studied parameters under stress with dual inoculation. The results therefore signify the importance of rhizobia and mycorrhizal inoculation for imparting stress tolerance in soybean.