Metabolite and Phytohormone Profiling Illustrates Metabolic Reprogramming as an Escape Strategy of Deepwater Rice during Partially Submerged Stress

Rice varieties that can survive under submergence conditions respond to flooding either by enhancing internode elongation or by quiescence of shoot elongation. Despite extensive efforts to identify key metabolites triggered by complete submergence of rice possessing SUBMERGENCE 1 (SUB1) locus, metabolic responses of internode elongation of deepwater rice governed by the SNORKEL 1 and 2 genes remain elusive. This study investigated specific metabolomic responses under partial submergence (PS) to deepwater- (C9285) and non-deepwater rice cultivars (Taichung 65 (T65)). In addition, we examined the response in a near-isogenic line (NIL-12) that has a C9285 genomic fragment on chromosome 12 introgressed into the genetic background of T65. Under short-term submergence (0–24 h), metabolite profiles of C9285, NIL-12, and T65 were compared to extract significantly changed metabolites in deepwater rice under PS conditions. Comprehensive metabolite and phytohormone profiling revealed increases in metabolite levels in the glycolysis pathway in NIL-12 plants. Under long-term submergence (0–288 h), we found decreased amino acid levels. These metabolomic changes were opposite when compared to those in flood-tolerant rice with SUB1 locus. Auxin conjugate levels related to stress response decreased in NIL-12 lines relative to T65. Our analysis helped clarify the complex metabolic reprogramming in deepwater rice as an escape strategy.

Adaptasi Tanaman Padi Terhadap Stres Genangan: Biosintesis Etilen

Drastically environmental change when submergence occur cause physiologically damages in plant. Submergence inhibits the rate of gas diffusion between plant and atmosphere. The decrease of oxygen interfere the respiration and the inhibition of CO2 into plant disturbs the photosynthesis process. In addition, the plant also experience stress after submergence. There are two types of plant adaptation to submergence, namely tolerance and the elongation ability. The elongation of submerged stem is related to ethylene production. The exogenous ethylene application stimulate the elongation of deepwater rice in aerobic condition . Ethylene biosyntheses is arranged by ACC synthase gene.Versi pre-print