The ZFP36/ZFP252-OsDOG1L1-OsPP2Cs module regulates seed germination in rice

Seed germination is a complex, multistep developmental process that is critical for plant growth and regulated by intricate polygenic networks. Despite its agronomic significance, the precise mechanism underlying this process in rice remains incompletely understood. In this study, we determined a seed-specific gene OsDOG1L1, the ortholog of Arabidopsis DOG1, as an essential regulator that inhibits germination while promoting seed dormancy in rice. Overexpression of OsDOG1L1 led to delayed germination and enhanced dormancy, whereas loss-of-function mutants showed accelerated germination and reduced dormancy. Temporal analysis showed a progressive decline in OsDOG1L1 transcript and protein levels during germination. Furthermore, we identified two C2H2-type zinc finger transcription factors, ZFP36 (also known as Bsr-d1) and ZFP252, as direct regulators of OsDOG1L1, functioning upstream to repress OsDOG1L1 expression. Molecular and genetic analyses demonstrated that OsDOG1L1 interacts with and suppresses the phosphatase activity of clade A protein phosphatase 2Cs (PP2Cs), OsPP2C09 and OsPP2C30, thereby enhancing ABA signaling to inhibit seed germination. Together, our findings uncover a ZFP36/ZFP252-OsDOG1L1-OsPP2Cs regulatory module that governs rice seed germination, providing insights into the molecular regulation of germination control in rice.