水稻独脚金内酯信号感知的激活和终止OA北大核心CSTPCD

Strigolactone(SL)is a novel plant hormone that regulates important growth and developmental processes such as plant branching.In rice,the SL receptor D14 perceives SL signals,binds with the F-box protein D3,and recruits the transcriptional repressor D53,inducing the ubiquitination and degradation of D53,thereby triggering signal transduc-tion and inhibiting tillering.A recent study discovered that nitrogen limitation induces SL biosynthesis in rice to activate the receptor D14,triggering SL signal transduction.Concurrently,nitrogen limitation also induces phosphorylation of the N-terminal disordered region(NTD)of D14,reducing the ubiquitination and degradation of receptor D14,thereby further enhancing SL perception.Through these two synergistic mechanisms,nitrogen limitation stimulates SL signal transduc-tion,strongly inhibiting tillering and enabling rice to adapt to low nitrogen stress conditions.The study also found that the D14-D3 interaction induced by SL promotes the ubiquitination and degradation of D14,thereby mediating the termination of SL signal perception.These significant findings elucidate the mechanisms of activation and termination of SL percep-tion in rice,revealing the crucial regulatory role of SL signals in controlling rice tillering under low nitrogen stress.This would provide key insights into plant adaptation to nutrient scarcity and guide the precise improvement of crop architec-ture and molecular breeding of rice for reduced fertilizer use and increased yield.