第1110回生物科学セミナー

Integration of hormonal and transcriptional control during vascular development

Prof. Ykä Helariutta(University of Cambridge)

2016年09月14日(水)    16:30-18:00  理学部2号館 講堂   

Vascular plants have a long-distance transport system consisting of two tissue types, phloem and xylem. During root primary development, xylem is specified early as an axis of vessel element cell files, whereas phloem is established through a set of asymmetric cell divisions also contributing to the intervening procambial tissue (Mähönen et al. 2000 Genes Dev). Auxin and cytokinins interact to specify the xylem and phloem/procambial domains, respectively (Mähönen et al. 2006 Science; Bishopp et al. 2011 Curr Biol). Furthermore, auxin promotes expression of the class III HD-ZIP genes (whose expression domain is specified by the ground-tissue originating miR165/6) to promote xylem identity (Carlsbecker et al. 2010 Nature, Ursache et al. 2012 Development). By taking advantage of a tool with which we can control plasmodesmatal trafficking (Vaten et al. 2011 Developmental Cell), we identified a group of mobile transcription factors that mediate the specification of phloem/procambial domain downstream of cytokinins. Their interaction with the class III-ZIP genes to integrate the hormonal signaling is discussed.