Vacuole Integrity Maintained by DUF300 Proteins Is Required for Brassinosteroid Signaling Regulation  

作　　者：Qinsong Liu Thomas Vain Corrado Viotti Siamsa M, Doyle Danuse Tarkowska Ondrej Novak Cyril Zipfel Folke Sitbon Stephanie Robert Daniel Hofius 

机构地区：[1]Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences (SLU) and Linnean Center for Plant Biology, PO Box 7080, 750 07 Uppsala, Sweden [2]Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences (SLU), 90183 Umea, Sweden [3]Umea Plant Science Centre, Umea University, 90187 Umea, Sweden [4]Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, 14476 Potsdam, Germany [5]Laboratory of Growth Regulators, Centre of the Region Hana for Biotechnological and Agricultural Research, institute of Experimental Botany ASCR and Palacky University, 783 71 Olomouc, Czech Republic [6]The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK [7]These authors contributed equally to this article. [8]Present addresses: Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), College of Life Science, China West Normal University, Nanchong 637009, Sichuan, China [9]Institut de Biologie Moleculaire des Plantes du CNRS, IBMP-CNRS, UPR2357, 12 rue du General Zimmer, 67084 Strasbourg, France

出　　处：《Molecular Plant》2018年第4期553-567,共15页分子植物（英文版）

摘　　要：Brassinosteroid （BR） hormone signaling controls multiple processes during plant growth and development and is initiated at the plasma membrane through the receptor kinase BRASSINOSTEROID INSENSITIVE1 （BRI1） together with co-receptors such as BRI1-ASSOClATED RECEPTOR KINASE1 （BAK1）. BRI1 abun- dance is regulated by endosomal recycling and vacuolar targeting, but the role of vacuole-related proteins in BR receptor dynamics and BR responses remains elusive. Here, we show that the absence of two DUF300 domain-containing tonoplast proteins, LAZARUS1 （LAZl） and LAZl HOMOLOG1 （LAZlH1）, causes vacuole morphology defects, growth inhibition, and constitutive activation of BR signaling. Intriguingly, tonoplast accumulation of BAK1 was substantially increased and appeared causally linked to enhanced BRI1 trafficking and degradation in lazl lazlhl plants. Since unrelated vacuole mutants exhibited normal BR responses, our findings indicate that DUF300 proteins play distinct roles in the regulation of BR signaling by maintaining vacuole integrity required to balance subcellular BAK1 pools and BR receptor distribution.Brassinosteroid （BR） hormone signaling controls multiple processes during plant growth and development and is initiated at the plasma membrane through the receptor kinase BRASSINOSTEROID INSENSITIVE1 （BRI1） together with co-receptors such as BRI1-ASSOClATED RECEPTOR KINASE1 （BAK1）. BRI1 abun- dance is regulated by endosomal recycling and vacuolar targeting, but the role of vacuole-related proteins in BR receptor dynamics and BR responses remains elusive. Here, we show that the absence of two DUF300 domain-containing tonoplast proteins, LAZARUS1 （LAZl） and LAZl HOMOLOG1 （LAZlH1）, causes vacuole morphology defects, growth inhibition, and constitutive activation of BR signaling. Intriguingly, tonoplast accumulation of BAK1 was substantially increased and appeared causally linked to enhanced BRI1 trafficking and degradation in lazl lazlhl plants. Since unrelated vacuole mutants exhibited normal BR responses, our findings indicate that DUF300 proteins play distinct roles in the regulation of BR signaling by maintaining vacuole integrity required to balance subcellular BAK1 pools and BR receptor distribution.

关 键 词：brassinosteroid signaling vacuole integrity DUF300 proteins TONOPLAST Arabidopsis 

分 类 号：Q51[生物学—生物化学] Q942