PGPR assisted bioremediation of heavy metals and nutrient accumulation in Zea mays under saline sodic soil

摘要

An experiment was conducted to evaluate the effects of four plant growth promoting rhizobacteria; Pseudomonas putida, Bacillus pumilus, Lysinibacillus sphaericus and Exiguobacterium aurantiacum isolated from saline soil on the uptake, accumulation and translocation of essential nutrients and heavy metals in Zea mays L. grown in saline sodic field. The PGPR exhibited significant increases in Na, K, Ca, Fe and Zn concomitant with significant decreases in Cd and Ni contents were recorded in the rhizosphere soil of maize inoculated with Pseudomonas putida. The PGPR increased availability of Fe and Zn in the rhizosphere soil, their uptake in roots and its translocation to leaves and grain. Bacillus pumilus effectively decreased Cd, Ni and Pb accumulation in grains whereas, Ni, Pb, Cr and Cd accumulation were more effectively reduced in leaves and grains of Pseudomonas putida inoculated plants . Pseudomonas putida increased biological accumulation coefficient of Cr, biological concentration factor for Cr, Cd and Ni but increased translocation factor for Pb. Whereas, Bacillus pumilus enhanced TF for Cd and Pb. Bacillus pumilus inoculated plants had significantly lower Na and K but had higher Ca, Fe and Zn over C. Pseudomonas putida and Bacillus pumilus can be implicated for enhanced bioremediation of heavy metals and for increased Zn and Fe accumulation in leaves and grain.