Cytokinin Perception Also Starts at the Plasma Membrane

• 作 者: M. Arif Ashraf
• 机 构: Department of Biology,University of Massachusetts Amherst,Amherst,MA,USA
• 出 处: 分子植物（英文版）
• 发表日期: 2020年11期

The plant hormone cytokinin regulates diverse biological pro-cesses,including embryogenesis,cell division and differentia-tion,root and shoot architecture,vascular development,and formation of shoot and root lateral organs.The endoplasmic retic-ulum(ER)is considered as the primary cytokinin perception site based on the known subcellular localization of the cytokinin re-ceptors.In the canonical cytokinin signaling pathway,the percep-tion of cytokinin starts with the CHASE domain-containing AHK(Arabidopsis histidine kinase)receptors,which are located primar-ily in the ER.Upon perception through AHKs,AHPs(Arabidopsis histidine phosphotransferases)act as intermediates to transfer a phosphate from AHKs to the downstream type B ARRs(Arabidop-sis response regulators)for initiating a cytokinin-mediated tran-scriptional response.A previous study,however,suggested that cytokinin signaling could also initiate from the plasma membrane(PM)(Zürcher et al.,2016).Two recent reports confirmed the role of PM-localized AHKs in the perception of extracellular cytokinin.