Fig. 7: Proposed working model for the regulation of anaerobic germination in rice by OsGF14h.

A 14-3-3 protein, OsGF14h^WR04-6 acts as an ABA signal switch that activates a transcription-repressor OsHOX3 and inhibits a transcription activator OsVP1 by the strong interaction. On the one hand, the downstream ABA-regulation TFs and ABA-responsive genes Rab16A and OsEM1 are suppressed due to the ABA receptor OsPYL5 (a core positive regulator of the ABA signal transduction pathway in seed germination and early seedling growth) is inhibited by OsHOX3. On the other hand, ABA-responsive genes are also inhibited due to the functional weakening of the OsVP1-TRAB1 regulatory unit. Meanwhile, OsGF14h and OsHOX3 can transactivate unknown downstream genes to promote GA biosynthesis. So far, the balance of ABA signaling and GA biosynthesis pathway triggered by OsGF14h^WR04-6 finally enhanced the anaerobic germination and anaerobic seedling development ability for weedy rice. In contrast, OsGF14h^SN9816, as a partial loss-of-function 14-3-3 protein, attenuates interaction with OsHOX3 and OsVP1, resulting in the release of inhibition on OsPYL5, whereupon ABA response becomes sensitive and weak germination under the flooding stress.