OsAE7 Interacts With ZFP36 to Mediate Antioxidant Defense in Rice

Abscisic acid (ABA) plays a crucial role in plants' adaptation to drought and salinity. This study used Y2H (Yeast two‐hybrid system), GST pull‐down, and LCI (Firefly luciferase complementation imaging assay) approaches to reveal the role of the interaction between OsAE7 (asymmetric leaves1/2 enhancer 7) and ZFP36 (zinc finger protein 36) in rice. Subcellular localization analysis revealed that OsAE7 is localized in the nucleus. After treatment with ABA, H2O2, osmotic stress (polyethylene glycol, PEG), and NaCl, the expression level of OsAE7 genes in leaves has increased. Experiments with H2O2 scavenger (DMTU) and NADPH oxidase inhibitor (DPI) indicated that ABA induces the up‐regulation of OsAE7 expression through increased ROS production. The OsAE7 gene knockout mutant osae7‐KO was constructed using the CRISPR/Cas9 system and Agrobacterium‐mediated method, and T1 generation homozygous lines osae7‐1 and osae7‐2 were obtained. Under simulated stress with PEG and NaCl, the antioxidant defense enzyme activity, relative water content, and proline content of the osae7‐KO mutant were significantly lower than those of the wild type, while the malondialdehyde content and relative plasma membrane permeability were significantly higher, indicating that the osae7‐KO mutant has lower stress resistance. osae7‐KO plants were also much less sensitive to ABA than the wild type. qRT‐PCR analysis showed that the interaction with ZFP36 affects the induction of OsAE7 by ABA. In conclusion, OsAE7 is involved in the ABA signaling pathway and plays a role in the plant's response to drought and salt stresses.