Enhancing okra tolerance to salinity stress: role of PGPR and antioxidant enzymes

Salinity stress is a major constraint on global crop productivity, necessitating sustainable strategies to enhance plant resilience. Plant growth-promoting rhizobacteria (PGPR) with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity have emerged as promising candidates for mitigating salt stress in crops. The present study evaluated the potential of PGPR isolates in improving salinity tolerance of okra (Abelmoschus esculentus L.). Growth performance, chlorophyll content, and antioxidant enzyme activities-superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)-were assessed under salinity stress conditions. PGPR inoculation significantly enhanced growth attributes, increased chlorophyll content, and improved antioxidant enzyme activity in stressed okra plants compared to uninoculated controls. Among the tested isolates, Caballeronia sp. AS11 showed the most pronounced improvement in plant growth and oxidative stress mitigation. These findings highlight the potential of ACC deaminase-producing PGPR, particularly Caballeronia sp. AS11, as bioinoculants for enhancing salinity tolerance in okra. The application of such beneficial microbes offers a sustainable approach to improve crop productivity in saline-prone environments.