Exploitation of IAA Producing PGPR on mustard (Brassica nigra L.) seedling growth under cadmium stress condition in comparison with exogenous IAA application

Soil pollution by cadmium (Cd) is a global threat for plants and animals. Exogenous auxin application reduces the Cd stress on plants. Moreover, IAA production by rhizospheric bacteria can play a key role in plant growth and development by promoting cell division, cell elongation, cell differentiation, flowering and lateral root formation. The present study was to evaluate the efficiency of IAA producing, Cd tolerant plant growth promoting rhizobacteria for plant (Brassica nigra L.) growth under Cd stressed condition comparing with the external synthetic auxin application. Lysinibacillus varians and Pseudomonas putida were isolated previously as IAA producing PGPR and selected in this study for their exploitation in plant growth development under Cd stressed condition. The impact of external synthetic IAA application significantly increased the plant growth under Cd amended soil. Whereas, PGPR inoculation also showed significant (p<0.05) elevation in germination percentage, root and shoot length, chlorophyll content and other growth parameters of Cd stressed Brassica plants which were comparative to synthetic IAA application. So, these selected PGPRs (L. varians and P. putida) can be used as biofertilizer which ameliorate the adverse effect of cadmium