Ameliorative effect of co-application ofBradyrhizobium japonicumEI09 and Se to mitigate chromium stress inCapsicum annumL.

The present study was conducted to explore the potential ofBradyrhizobium japonicumEI09 (EI09) and selenium (Se) alone or in combination to mitigate hexavalent chromium (Cr6+) stress inCapsicum annumL. Chromium stressed plants exhibited significant reduction in biomass, chlorophyll content and gas exchange characteristics. The inoculated seedlings subjected to Cr(6+)stress showed improvement in growth, proline content, gas exchange attributes and total soluble proteins. Likewise, inoculatedC. annumseedlings exhibited augmented activity of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) under Cr(6+)stress. The Cr(6+)stress mitigation in inoculated seedlings was ascribed to reduction in malondialdehyde (MDA) content, hydrogen peroxide (H2O2) besides increase activity of flavonoids, proline, phenolic content along with modulation of antioxidative enzymes. The growth-enhancing attributes of bacteria such as indole acetic acid (IAA) content and 1-aminocyclopropane-1-carboxylate deaminase (ACCD) activity enhanced growth in Cr6+-stressed plants. Moreover, co-treatment of EI09 and 5 mu M Se effectively mitigated Cr (VI) stress inC. annumplants. Current studies provide a novel insight into potential ofB. japonicumEI09 and Se in reduction of Cr(6+)toxicity inC. annumplants.