Fig. 5.

Model of interactions between the germination repressors OPDA, MFT, and ABA. OPDA promotes MFT gene expression (a; Fig. 4A, 4B) and MFT protein is required for OPDA accumulation (b; Fig. 4F). ABA also promotes MFT expression (c; Xi et al., 2010) and MFT is required for OPDA-driven ABA accumulation (d; Fig. 4D). RGL2 is necessary for OPDA accumulation (e; Fig. 3B), MFT expression (f; Xi et al., 2010), and OPDA-driven ABA accumulation (g; Fig. 2D). GA triggers RGL2 protein degradation (h; Murase et al., 2008). The reciprocal positive feedback between OPDA and ABA (Figs 2C and 3A) may happen through MFT (a and d; c and b) or another indirect pathway (i). OPDA and MFT may per se have ABA-independent germination inhibitory effects. For simplicity, the involvement of ABI5 has not been depicted in this model.