Genome wide identification of the RhoGAP gene family and functional analysis of OsRhoGAP2 in seed germination of rice

Using CRISPR-Cas9 mediated gene editing, we generated a loss-of-function mutant of OsRhoGAP2 (rhogap2) and found that seed germination was significantly delayed compared to the wild type. Further analysis revealed that alpha-amylase activity was reduced in rhogap2 germinating seeds. RNA-seq profiling identified 291 upregulated and 130 downregulated genes in the mutant, with differentially expressed genes (DEGs) primarily enriched in phenylpropanoid biosynthesis and other metabolic pathways. Notably, most phenylpropanoid biosynthesis-related genes exhibited increased expression in rhogap2 germinating seeds. These findings establish a foundational framework for future functional studies of RhoGAP genes in rice and provide novel insights into the molecular mechanisms by which RhoGAPs regulate seed germination in plants.