Petal size is determined by cell division and cell expansion. Jasmonic acid (JA) has been reported to be associated with floral development, but its regulatory mechanism affecting petal size remains unclear. Here, we reveal the vital role of JA in regulating petal size and the duration of the cell division phase via the key JA signaling component RhMYC2. We show that RhMYC2 expression is induced by exogenous treatment with methyl jasmonate and decreases from stage 0 to stage 2 of flower organ development, corresponding to the cell division phase. Furthermore, silencing RhMYC2 shortened the duration of the cell division phase, ultimately accelerating flowering opening and resulting in smaller petals. In addition, we determined that RhMYC2 controls cytokinin homeostasis in rose petals by directly activating the expression of the cytokinin biosynthetic gene LONELY GUY3 (RhLOG3) and repressing that of the cytokinin catabolism gene CYTOKININ OXIDASE/DEHYDROGENASE6 (RhCKX6). Silencing RhLOG3 shortened the duration of the cell division period and produced smaller petals, similar to RhMYC2 silencing. Our results underscore the synergistic effects of JA and cytokinin in regulating floral development, especially for petal size in roses.
PJ:中国农大发现水稻感性重力信号的新基因
分蘖角度是水稻的一个重要农艺性状。本研究发现一个C3H2C3-type RING zinc finger E3 ligase-LARGE TILLER ANGLE 1 (LATA1)参与了水稻分蘖角度的调控。LATA1在根系和分蘖基部高表达，通过定位分析发现该基因定位于细胞核。突变LATA1 会显著降低indole-3-acetic acid水平并且抑制了生长素的转运，从而造成地上部向地性被强化，分蘖角度显著增加。
LATA1 可以通过间接调控重力感应的造粉体的沉积而影响对重力信号的识别。
原文：LATA1, a RING E3 ligase, modulates the tiller angle by affecting auxin asymmetric distribution and content in rice
