Responses of the antioxidative enzymes of few Sub1 rice (Oryza sativa) genotypes to prolonged submergence stress in Odisha

Abstract

The present experiment was conducted in Department of Plant physiology, OUAT, Bhubaneswar during kharif 2017 and kharif 2019 to screen out the NILs rice genotypes for submergence adaptation traits under coastal regions of Odisha. The potential involvement of activated oxygen species by submergence stress was studied in twenty rice genotypes; thirteen sub1 NILs, two tolerant checks with six susceptible checks. These rice genotypes were subjected to 17 days of complete submergence. Under 17 days of complete submergence and after the submergence, the genotypes IR-85086-Sub 33 -3-2-1 and IR-88760-Sub 93-3-3 showed lower lipid Peroxidation in terms of malondialdehyde (MDA) level and also showed lower levels of ACC Oxidase activity (AAO) and presented higher activities of antioxidative enzymes, superoxide dismutase (SOD), catalase (CAT), Peroxidase (POX) when compared to the susceptible checks. The levels of SOD activity indicated that detoxification of O2 - to H2O2 was maintained at a stable level throughout the submergence stress until up to 17 days in tolerant genotypes. These findings suggested that tolerance to submergence stress in rice might be proven by increased the capacity of antioxidative system. In addition, SOD and CAT activity has much higher affinity for scavenging H2O2 than POX. The present study evaluated thirteen pairs of Sub1 near-isogenic lines (NILs) together with FR13A and other check genotypes in pot culture conditions to assess the survival and growth processes occurring during submergence and recovery that are associated with Sub1.