Cytokinins regulate spatially specific ethylene production to control root growth in Arabidopsis  

作　　者：Amel Yamoune Marketa Zdarska Thomas Depaepe Anna Rudolfova Jan Skalak Kenneth Wayne Berendzen Virtudes Mira-Rodado Michael Fitz Blanka Pekarova Katrina Leslie Nicolas Mala Paul Tarr Eliska Spackova Lucia Tomovicova Barbora Parizkova Abigail Franczyk Ingrid Kovacova Vladislav Dolgikh Elena Zemlyanskaya Marketa Pernisova Ondrej Novak Elliot Meyerowitz Klaus Harter Dominique Van Der Straeten Jan Hejatko 

机构地区：[1]CEITEC(Central European Institute of Technology),Masaryk University,Brno,Czech Republic [2]National Centre for Biomolecular Research,Faculty of Science,Masaryk University,Brno,Czech Republic [3]Laboratory of Functional Plant Biology,Department of Biology,Ghent University,Gent,Belgium [4]Center for Plant Molecular Biology,University of Tübingen,Tübingen,Germany [5]Howard Hughes Medical Institute and Division of Biology and Biological Engineering,California Institute of Technology,Pasadena,CA,USA [6]Faculty of Science,PalackýUniversity and Institute of Experimental Botany,The Czech Academy of Sciences,Olomouc,Czech Republic [7]Institute of Cytology and Genetics,Siberian Branch,Russian Academy of Sciences,Novosibirsk 630090,Russia [8]Faculty of Natural Sciences,Novosibirsk State University,Novosibirsk 630090,Russia

出　　处：《Plant Communications》2024年第11期99-115,共17页植物通讯（英文）

基　　金：Ministry of Education,Youth and Sports of the Czech Republic under the projects TANGENC(CZ.02.01.01/00/22_008/0004581)and LUAUS24277;German Research Foundation(CRC 1101 project D02);Howard Hughes Medical Institute(to E.M.M.);Russian Science Foundation(20-14-00140).

摘　　要：Two principal growth regulators,cytokinins and ethylene,are known to interact in the regulation of plant growth.However,information about the underlying molecular mechanism and positional specificity of cytokinin/ethylene crosstalk in the control of root growth is scarce.We have identified the spatial specificity of cytokinin-regulated root elongation and root apical meristem(RAM)size,both of which we demonstrate to be dependent on ethylene biosynthesis.Upregulation of the cytokinin biosynthetic gene ISOPENTENYLTRANSFERASE(IPT)in proximal and peripheral tissues leads to both root and RAM shortening.By contrast,IPT activation in distal and inner tissues reduces RAM size while leaving the root length comparable to that of mock-treated controls.We show that cytokinins regulate two steps specific to ethylene biosynthesis:production of the ethylene precursor 1-aminocyclopropane-1-carboxylate(ACC)by ACC SYNTHASEs(ACSs)and its conversion to ethylene by ACC OXIDASEs(ACOs).We describe cytokinin-and ethylene-specific regulation controlling the activity of ACSs and ACOs that are spatially discrete along both proximo/distal and radial root axes.Using direct ethylene measurements,we identify ACO2,ACO3,and ACO4 as being responsible for ethylene biosynthesis and ethylene-regulated root and RAM shortening in cytokinin-treated Arabidopsis.Direct interaction between ARABIDOPSIS RESPONSE REGULATOR 2(ARR2),a member of the multistep phosphorelay cascade,and the C-terminal portion of ETHYLENE INSENSITIVE 2(EIN2-C),a key regulator of canonical ethylene signaling,is involved in the cytokinin-induced,ethylene-mediated control of ACO4.We propose tight cooperation between cytokinin and ethylene signaling in the spatially specific regulation of ethylene biosynthesis as a key aspect of the hormonal control of root growth.

关 键 词：CYTOKININ ETHYLENE ACC SYNTHASE ACC OXIDASE multistep phosphorelay ARABIDOPSIS 

分 类 号：Q945[生物学—植物学]