A K+-Efflux Antiporter is Vital for Tolerance to Salt Stress in Rice.

Salt damage significantly affects rice growth and development, posing a threat to food security. Understanding the mechanisms underlying rice's response to salt stress is crucial for enhancing its tolerance. This study aimed to elucidate the genetic and physiological mechanisms of rice adaptation to salt stress. We found that the expression of OsKEA1, a potassium (K⁺)-efflux antiporter gene in rice, was induced by salt. Both genetic and physiological experiments demonstrated that the mutation in OsKEA1 disrupted the Na⁺/K⁺ balance under salt stress conditions. Furthermore, OsKEA1 mutation exacerbated reactive oxygen species (ROS) accumulation, disrupted the antioxidant enzyme system, and compromised chloroplast integrity under salt stress. This study unveils the adaptive mechanisms of rice to salt damage and highlights the critical role of OsKEA1 in managing salt stress.