Microbial amelioration of salinity stress in HD 2967 wheat cultivar by up-regulating antioxidant defense.

An experiment was conducted to investigate the potential of and plant growth-promoting bacteria (PGPB) to ameliorate salinity stress in HD 2967 wheat cultivar. Plants were treated with four different levels of salinity viz. 0, 50, 100 and 200 mM NaCl (electrical conductivity value 0.01, 5.84, 11.50 and 21.4 mS cm, respectively) under greenhouse conditions, using a completely randomized design experiment. Plants inoculated with PGPB and showed decrease in lipid peroxidation, relative membrane permeability and lipoxygenase enzyme (LOX) activity as compared to uninoculated plants. The result of this study showed that PGPB and inoculated HD 2967 wheat plants accumulated higher content of proline, α-tocopherol and carotenoid as compared to uninoculated plants. The HD 2967 wheat plants either inoculated with PGPB or showed significantly higher activities of antioxidant enzymes viz. superoxide dismutase, catalase and ascorbate peroxidase than that of the uninoculated plants. Moreover, PGPB inoculated plants showed greater activity of antioxidant enzymes than the plants inoculated with . Salinity stress tolerance was more pronounced in the PGPB inoculated than inoculated plants. This study revealed the potentiality of PGPB and as bio-ameliorator under salinity stress, and suggests that this plant microbial association could be a promising biotechnological tool to combat the deleterious effects of salinity stress.