The LARGE2-APO1/APO2 regulatory module controls panicle size and grain number in rice

Abstract Panicle size and grain number are important agronomic traits influence yield in rice (Oryza sativa), but the molecular genetic mechanisms underlying panicle control remain largely unknown crops. Here we report that LARGE2 encodes a HECT-domain E3 ubiquitin ligase OsUPL2 regulates rice. The loss of function large2 mutants produce large panicles with increased number, wide grains leaves, thick culms. by repressing meristematic activity. is highly expressed young grains. Biochemical analyses show physically associates ABERRANT PANICLE ORGANIZATION1 (APO1) APO2, two positive regulators modulates their stabilities. Genetic support functions APO1 APO2 common pathway to regulate number. These findings reveal novel mechanism LARGE2-APO1/APO2 module-mediated rice, suggesting this module promising target for improving