Peanut 9--epoxycarotenoid Dioxygenase Enhances Salt and Drought Stress Tolerance by Regulating ROS Homeostasis.

Peanut ( L.), a vital oilseed and cash crop, faces yield limitations due to abiotic stresses. The 9--epoxycarotenoid dioxygenase (NCED) enzyme, a key enzyme in abscisic acid (ABA) biosynthesis regulating plant development and stress responses, remains mechanistically uncharacterized in peanut abiotic stress tolerance. In this study, we isolated a novel gene, , from the salt-tolerant mutant M24. The expression of was strongly induced by NaCl, PEG6000, and ABA in peanut huayu20. Overexpression of enhanced salt and drought tolerance in . Transgenic overexpression of improved salt and stress resistance through upregulated ROS-scavenging genes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) with elevated enzymatic activities while reducing malondialdehyde (MDA), superoxide anion (O), and hydrogen peroxide (HO) accumulation compared to wild-type plants. Further research showed that the chlorophyll fluorescence parameters of transgenic lines were significantly increased, while light damage was significantly reduced. These findings establish as a critical regulator of stress adaptation and an excellent candidate gene for resistance breeding in peanut.