Vermiwash Mediated Salt Stress Amelioration in Brassicaceae Crops

Salt stress is a common abiotic stress that increases the production of reactive oxygen species (ROS), which are toxic to plants and cause oxidative stress. Vermiwash, a liquid extract from vermicompost, is used in organic farming as a bio-fertilizer and growth promoter to mitigate various stresses. However, it's potential in alleviating salt stress in Brassicaceae crops like turnip (Brassica rapa L.) and radish (Raphanus sativus L.) is not well known. This experiment investigated the protective effects of vermiwash on turnip cultivar (L-1) and radish cultivar (Pusa Chetki) under 100 mM NaCl salt stress. Four concentrations of vermiwash (25, 50, 75, and 100%) were applied to assess its impact. NaCl-induced phytotoxicity reduced germination parameters, relative water content (RWC), fresh and dry weight, root and shoot length, photosynthetic pigments, protein content, and antioxidant activities. It also increased proline, malondialdehyde (MDA), hydrogen peroxide (H2O2), percent ion leakage, and superoxide anion levels, causing membrane damage and reduced cellular viability in turnip and radish seedlings. Exogenous application of vermiwash alleviated salt toxicity, improving germination paramters, RWC, fresh and dry weight, root and shoot length, chlorophyll content, carotenoid content, lycopene, beta-carotene, protein content, and antioxidant activities. Vermiwash reduced proline, superoxide anion, MDA, and H2O2 levels, and percent ion leakage, enhancing plant water relations, photosynthetic and antioxidant capacity, and ion homeostasis. Histochemical analysis showed that vermiwash reduced cell death, lipid peroxidation, and superoxide accumulation, protecting cells during salt stress. These results highlight vermiwash's role in mitigating salt-induced oxidative stress in turnip and radish seedlings.