Tailoring the rhizospheric microbiome of Vigna radiata by adaptation to salt stress

Sustainable management practices are the need of the hour to counter the ever-deteriorating environmental conditions in agro-ecosystems. While bioinoculants have served as eco-friendly means to mitigate stresses, their survivability and competitiveness in field conditions have been a major challenge. The present study aimed to adopt a multi-generational approach to adapt the rhizospheric microbiome of Vigna radiata, a legume consumed worldwide, under salt stress. A multi-generational plant growth experiment was set-up with induced salinity stress, employing the rhizosphere of best-performing plants from the preceding generation as inoculum for the next generation. The plant health and mitigation of salinity stress by the adapted microbiome was analyzed using plant biometrics, bacterial diversity, and stress markers. Decreased levels of salt-induced stress markers, and simultaneous improvement in plant attributes were observed with the progression of the generations. The shifts in bacterial community were prominent upon inoculation of the adapted microbiome. The treatments with the adapted microbiome in the presence of salinity stress were closer to the control sets compared to salinity-stressed treatments, indicating the efficiency of the adapted microbiome towards mitigation of salinity stress. The study demonstrates the promising potential of such an eco-friendly, microbiome-based approach for plant growth promotion and mitigation of salinity stress.