Seminars

Cell wall modification is one ofthe essential activities to sustain plant life cycles by building barriers formaintaining their homeostasis or adjusting physical properties fordevelopmental processes and stress responses. Among various types of cell wallmodifications,  Casparian strip, which functions as a root  apoplastic barrier, forms a longitudinal ring structure in the central position ofendodermal surface. In order to elucidate how the  Casparian strips are formed in a molecular level, we conducted a forward genetic screenby direct visualization of root barrier function. During the screen, weidentified 5 independent mutants including a receptor-like kinase and an NADPHoxidase which are essential for functional  Casparian strip formation (Lee et al. 2013,  Pfister et al. 2014,  Alassimone and Fujita et al. 2016). Moreover, two groups independently reported peptideligands of the receptor-like kinase and showed the peptides were expressed inthe steles, suggesting non-cell autonomous regulation is required forestablishing functional  Casparian strips in the endodermis ( Doblas et al. 2017, Nakayama et al. 2017). However, how this signaling pathwaycoordinate the  Casparian strip formation at molecular or tissue levels is still unclear. Here, I willpresent localized ROS production around  Casparian strips as a downstream event of the peptide / receptor signaling pathway.Furthermore, possible spatial regulation of this signaling pathway at thetissue level will be discussed.
References :Lee et al. (2013)  Cell ,Pfister et al. (2014)  eLife ,Alassimone and Fujita et al. (2016)  Nature Plants ,Doblas et al. (2017)  Science ,Nakayama et al.  (2017)  Science