Effect of plant growth-promoting rhizobacterial treatment on growth and physiological characteristics of Triticum aestivum L. under salt stress

Salinity stress is a serious abiotic stress that affects crop quality and production. Rhizospheric microbes have immense potential in synthesizing and releasing various compounds that regulate plant growth and soil physicochemical properties. The aim of the present study was to evaluate the efficacy of indole-3-acetic acid (IAA)-producing rhizobacteria as biofertilizers under salt stress. Among the isolated strains from various soil samples, Bacillus megaterium strain PN89 with multifarious plant growth-promoting traits was selected and used as a monoculture and co-culture with two other standard strains. The plant promoting activity was evaluated using the paper towel method and pot test to observe the effects on the early stage and vegetative growth of wheat (Triticum aestivum L.). The treatment using PGPR strain presented noticeable but varying effects on plant growth under salt stress, that is, PGPR treatment often displayed a significant increase in germination percentage, root and shoot length, and other growth parameters of wheat compared to those in the non-inoculated control. Thus, these results suggest that B. megaterium PN89 can be applied as a bio-fertilizer to alleviate salt stress in T. aestivum.