The present invention discloses the effective application of Azospirillum brasilense strain KB1 in enhancement of nickel toxicity tolerance and phytoremediation potential of soybean plants. Azospirillum brasilense strain KB1 was able to grow and tolerate Ni stress up to 3 mM NiCl2 . Inoculation of nickel-stressed soybean plants with Azospirillum brasilense strain KB1 significantly promoted their growth, biomass, mineral uptake, antioxidant capacity, gas exchange characteristics, chlorophyll content and osmolytes biosynthesis. Furthermore, Azospirillum brasilense strain KB1 application mitigated oxidative stress markers levels, but significantly induced the activities of antioxidant enzymes and the expression levels of stressrelated genes in nickel-stressed plants. The present invention enhances our understanding of the regulatory mechanisms of nickel toxicity tolerance of soybean plants.
