Submergence tolerance regulator, SUB1A: Convergence of submergence and drought response pathways in rice

Abstract

Global climate change affects the frequency and magnitude of hydrological changes, resulting in catastrophic events like floods and drought. Extremes in precipitation, both high and low, are limiting food, fiber, and forest production across the globe. Rice (Oryza sativa) productivity on rain-fed farmlands is hampered by submergence and drought, both of which may occur simultaneously within a single crop cycle. With the successful introduction of flash flood-tolerant rice varieties to farmers over the past decade, molecular mechanisms of flood tolerance in rice have been uncovered. Despite intensive study, the breakthrough in drought tolerance has yet to be achieved. SUB1A, an ERF transcription factor identified in a small number of rice accessions, reduces ethylene synthesis and gibberellic acid response during submergence, conserving glucose stores and extending endurance greatly. SUB1A improves drought recovery during the vegetative stage by reducing leaf water loss and lipid peroxidation, as well as increasing the expression of genes linked with adaptation to dehydration, according to recent research. SUB1A overexpression increases ABA responsiveness, resulting in the activation of stress-inducible gene expression. During drought and de-submergence, SUB1A also prevents the formation of reactive oxygen species (ROS) in aerial tissue. SUB1A increases the number of transcripts encoding ROS scavenging enzymes on a consistent basis, resulting in improved oxidative stress tolerance. Thus, this review provides a detailed information about the effect of submergence and drought stress in rice and role of SUB1A in improving the survival of plants after rapid dehydration following de-submergence and water deficit during drought.