Ethylene-inhibited jasmonic acid biosynthesis promotes elongation of etiolated rice seedlings

During germination, the rice shoot is protected by the coleoptile, which is a highly light and hormone-sensitive tissue. While searching for genes involved in ethylene responses, Xiong et al. identified a mutant with an elongated coleoptile, in which the subtending mesocotyl is also elongated; they named this mutant gaoyao1 (gy1), a Chinese name meaning “high waist”. Map-based cloning revealed that GY1 encodes a plastid-localized phospholipase involved in the synthesis of jasmonic acid (JA). They found that ethylene (which promotes coleoptile elongation) represses expression of GY1, and that JA represses coleoptile growth. Furthermore, they found natural allelic variation of the GY1 gene associated with longer coleoptiles. These findings provide new insights into the regulation of seedling establishment and can be used to select for coleoptile length in breeding programs. Plant Cell 10.​1105/​tpc.​16.​00981