Butanolide alleviated cadmium stress by improving plant growth, photosynthetic parameters and antioxidant defense system of brassica oleracea.

Current study was performed to explore the effect of butanolide (KAR1) in mitigation of cadmium (Cd) induced toxicity in Brussels sprout (Brassica oleracea L.). Brussels sprout seeds, treated with 10-5 M, 10-7 M and 10-10 M solution of KAR1 were allowed to grow in Cd-contaminated (5 mg L-1) regimes for 25 d. Cadmium toxicity decreased seed germination and growth in B. oleracea seedlings. Elevated intensity of electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (H2O2) were observed in Cd-stressed seedlings. Additionally, reduced level of stomatal conductivity, transpiration rate, photosynthesis rate, intercellular carbon dioxide concentration, and leaf relative water content (LRWC) was also observed in Cd-stressed seedlings. Nevertheless, KAR1 improved seed germination, seedling growth and biomass production in Cd stressed plants. KAR1 application showed elevated LRWC, osmotic potential, and higher membranous stability index (MSI) in seedlings under Cd regime. Furthermore, seedlings developed by KAR1 treatment exhibited higher stomatal conductivity, and intercellular carbon dioxide concentration together with improved rate of transpiration and photosynthetic rate in B. oleracea under Cd stress. These findings elucidate that the reduced level of MDA, EL and H2O2, as well as improvement in antioxidative machinery increased growth and alleviated Cd toxicity in KAR1 treated seedlings under Cd stress.