Amelioration of drought tolerance in wheat by the interaction of plant growth‐promoting rhizobacteria

Abstract

Drought stress adversely affects the growth and yield of wheat. The present study was planned to investigate the effect of inoculation of plant-growth promoting rhizobacteria (PGPR) strains IG 3 (Klebsiella sp.), IG 10 (Enterobacter ludwigii) and IG 15 (Flavobacterium sp.) in improving drought tolerance in wheat. These PGPR strains were screened for drought tolerance in nutrient broth supplemented with different concentrations (0-25%) of polyethylene glycol (PEG6000). Effect of PGPR inoculation on various physiological, biochemical parameters and gene expression of stress responsive genes were studied under drought stress. Root colonization at the surface and interiors of roots was demonstrated using scanning electron microscopy (SEM) and tetrazolium staining, respectively. Drought stress significantly affected various growth parameters, water status, membrane integrity, osmolyte accumulation and stress-responsive gene expressions, which were positively altered by PGPR-inoculation in wheat. Quantitative real-time (qRT)-PCR analysis revealed the up regulation of some stress-related genes (DREB2A and CAT1) in un-inoculated wheat plants exposed to drought stress. PGPR-inoculated plants showed attenuated transcript levels suggesting improved drought tolerance due to interaction of PGPRs. The PGPR strain IG 3 was found to be the best in terms of influencing biochemical and physiological status of the seedlings under drought stress. Our report demonstrates the role of PGPRs Enterobacter ludwigii and Flavobacterium sp. in plant growth promotion of wheat plants under drought stress. The study reports the potential of PGPR in alleviating drought stress in wheat which could be used as potent biofertilizers.

The Coupling Effects of Plant Growth Promoting Rhizobacteria and Salicylic Acid on Physiological Modifications, Yield Traits, and Productivity of Wheat under Water Deficient Conditions

“…These findings are in congruence with earlier reports on the impact of PGPR on water deficit tolerance in maize, sunflower [44], and wheat [45]. Furthermore, PGPR-inoculated plants were successful in increasing the nitrogen, phosphorus, and potassium uptake into plant biomass [44,46]. Under water deficit, nutrient content (N-P-K) of plant biomass was improved when plants were treated with PGPR, perhaps owing to incremental root growth and root number that exploited more soil volume for efficient absorption of available essential nutrients [47], thus leading to higher biomass production [1].…”

“…Various reports depicted that PGPR can assist plants in tolerating water deficit, as indicated by the incremental soil aggregation and preserving of higher water potential around the roots, which in turn increased uptake of nutrients in plants exposed to water deficit [43]. These findings are in congruence with earlier reports on the impact of PGPR on water deficit tolerance in maize, sunflower [44], and wheat [45]. Furthermore, PGPR-inoculated plants were successful in increasing the nitrogen, phosphorus, and potassium uptake into plant biomass [44,46].…”

The Role of Plant-Associated Microbes in Mediating Host-Plant Selection by Insect Herbivores

“…Visual cues for insect herbivores related to host-plant quality are predominantly influenced by beneficial plant-associated microbes through enhanced or reduced plant growth or biomass. In general, beneficial microbes are predicted to increase plant biomass through enhanced nutrient acquisition [31], decreased drought stress [122,123], or production of growth-related phytohormones [124,125]. Although the effects of beneficial microbes on plant growth and biomass are well-documented, surprisingly few studies have evaluated the influence of these effects on insect herbivore foraging and oviposition.…”

Effect of bacterization with Aeromonas media GS4 and Pseudomonas extremorientalis PhS1 on wheat seedlings under different abiotic conditions

“…Plants undergo various stresses throughout their life, for example, drought and flooding, salinity, heat and cold, heavy metals, etc. [1][2]. Human needs for 129 high-quality products are growing and it is becoming hard to find suitable lands for agriculture and to obtain good low-cost crops [3].…”

“…Application of some microorganisms improving nitrogen and phosphorous nutrition of plants, having a stimulating effect and reducing infestation by phytopathogens, is one of the effective methods to enhance resistance of agricultural plants to stress abiotic factors [1,2,5,[13][14][15][16]. Therefore, a positive effect of plant treatment with different bacterial strains under abiotic stress is demonstrated in several studies.…”