Nucleobase-ascorbate transporter OsNAT9 regulates seed vigor and drought tolerance by modulating ascorbic acid homeostasis in rice.

ABSTRACT: Drought and seed aging severely impact crop yield and seed vigor, respectively. Here, we identified the rice protein OsNAT9, a nucleobase-ascorbate transporter, as being crucial for seed vigor and drought tolerance. Knockout of OsNAT9 resulted in a significant reduction in seed vigor; however, the application of exogenous ascorbic acid (AsA) and the breaking of seed dormancy restored this phenotype, suggesting that OsNAT9 regulates seed vigor by modulating seed dormancy. Furthermore, the Osnat9 mutants exhibited decreased AsA concentration in the endosperm, impairing the scavenging of reactive oxygen species (ROS) in aged seeds, which disrupted starch structure and seed vigor. During the aging process, both the knockout and overexpression of OsNAT9 affected AsA efflux, disrupting the redox

SUBMITTER: Liao S 

PROVIDER: S-EPMC12080319 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature