title: The WRKY Transcription Factor WRKY71/EXB1 Controls Shoot Branching by Transcriptionally Regulating RAX Genes in Arabidopsis.
abstract: Plant shoot branching is pivotal for developmental plasticity and crop yield. The formation of branch meristems is regulated by several key transcription factors including REGULATOR OF AXILLARY MERISTEMS1 (RAX1), RAX2, and RAX3. However, the regulatory network of shoot branching is still largely unknown. Here, we report the identification of EXCESSIVE BRANCHES1 (EXB1), which affects axillary meristem (AM) initiation and bud activity. Overexpression of EXB1 in the gain-of-function mutant exb1-D leads to severe bushy and dwarf phenotypes, which result from excessive AM initiation and elevated bud activities. EXB1 encodes the WRKY transcription factor WRKY71, which has demonstrated transactivation activities. Disruption of WRKY71/EXB1 by chimeric repressor silencing technology leads to fewer branches, indicating that EXB1 plays important roles in the control of shoot branching. We demonstrate that EXB1 controls AM initiation by positively regulating the transcription of RAX1, RAX2, and RAX3. Disruption of the RAX genes partially rescues the branching phenotype caused by EXB1 overexpression. We further show that EXB1 also regulates auxin homeostasis in control of shoot branching. Our data demonstrate that EXB1 plays pivotal roles in shoot branching by regulating both transcription of RAX genes and auxin pathways.
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Dongshu
authors.initials: D
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jinzhe
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Xinlei
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Han
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Baoye
authors.initials: B
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Jianqiao
authors.identifier: http://orcid.org/0000-0002-9810-1007
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Boxun
authors.identifier: http://orcid.org/0000-0002-4516-4418
authors.initials: B
authors.lastname: Li
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Qingpei
authors.initials: Q
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China The National Plant Gene Research Center (Beijing), Beijing 100101, People's Republic of China School of Advanced Agricultural Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Hongya
authors.identifier: http://orcid.org/0000-0003-2619-1522
authors.initials: H
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China The National Plant Gene Research Center (Beijing), Beijing 100101, People's Republic of China School of Advanced Agricultural Sciences, Peking University, Beijing 100871, People's Republic of China Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Li-Jia
authors.identifier: http://orcid.org/0000-0002-1765-7311
authors.initials: LJ
authors.lastname: Qu
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China School of Advanced Agricultural Sciences, Peking University, Beijing 100871, People's Republic of China qingenji@pku.edu.cn.
authors.forename: Genji
authors.identifier: http://orcid.org/0000-0002-6995-5126
authors.initials: G
authors.lastname: Qin
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D012097:Repressor Proteins; D014157:Transcription Factors; C000610964:WRKY71 protein, Arabidopsis