Fig. 6.

Model of hypothesized changes in spikelet architecture during Oryza evolution and putative function of LF1. During the evolutionary process the G1, EG1, OsMADS34, NSG, ASP1, and OsMADS1 genes determined the degeneration from the lemma to sterile lemma in lateral florets, whereas the miRNA165/166–LF1–OSH1 pathway controlled the degeneration of floral organs in lateral florets. Red arrows indicate positive regulation, the red “T” shape patterning indicates negative regulation, and green arrows show the two evolutionary lines of the WT spikelet. The blue arrows and “X” shape patterning suggest a possible method to breed a rice hybrid with a three-florets spikelet by combining the lf1 mutant and other materials with a lemma-like sterile lemma.