The LARGE1 controls grain size by repressing the interaction between PGL2 and APG in rice.

ABSTRACT: Grain size has long been recognized as a key determinant of yield potential in crops. Understanding the mechanisms governing grain size is critical for breeding high-yielding varieties. In a previous work, we revealed that the RNA-binding protein LARGE1 acts as a negative regulator of grain size and weight in rice. LARGE1 interacts with GSK2 (GLYCOGEN SYNTHASE KINASE2) and is phosphorylated by GSK2. Here, we report that LARGE1 physically interacts with an atypical non-DNA-binding bHLH protein PGL2 that positively influences grain size. Biochemical analyses show that PGL2 binds to APG, a typical DNA-binding bHLH protein that negatively regulates grain size. PGL2 suppresses the transcriptional activation activity of APG by forming the PGL2/APG heterodimer. Strikingly, LARGE1 can repress the

SUBMITTER: Liu Y 

PROVIDER: S-EPMC12811032 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature