title: The basic helix-loop-helix transcription factor MYC2 directly represses PLETHORA expression during jasmonate-mediated modulation of the root stem cell niche in Arabidopsis.
abstract: The root stem cell niche, which in the Arabidopsis thaliana root meristem is an area of four mitotically inactive quiescent cells (QCs) and the surrounding mitotically active stem cells, is critical for root development and growth. We report here that during jasmonate-induced inhibition of primary root growth, jasmonate reduces root meristem activity and leads to irregular QC division and columella stem cell differentiation. Consistently, jasmonate reduces the expression levels of the AP2-domain transcription factors PLETHORA1 (PLT1) and PLT2, which form a developmentally instructive protein gradient and mediate auxin-induced regulation of stem cell niche maintenance. Not surprisingly, the effects of jasmonate on root stem cell niche maintenance and PLT expression require the functioning of MYC2/JASMONATE INSENSITIVE1, a basic helix-loop-helix transcription factor that involves versatile aspects of jasmonate-regulated gene expression. Gel shift and chromatin immunoprecipitation experiments reveal that MYC2 directly binds the promoters of PLT1 and PLT2 and represses their expression. We propose that MYC2-mediated repression of PLT expression integrates jasmonate action into the auxin pathway in regulating root meristem activity and stem cell niche maintenance. This study illustrates a molecular framework for jasmonate-induced inhibition of root growth through interaction with the growth regulator auxin.
authors.affiliation: State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Jiaqiang
authors.initials: J
authors.lastname: Sun
authors.forename: Qingzhe
authors.initials: Q
authors.lastname: Zhai
authors.forename: Wenkun
authors.initials: W
authors.lastname: Zhou
authors.forename: Linlin
authors.initials: L
authors.lastname: Qi
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Bao
authors.initials: B
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.forename: Hongling
authors.initials: H
authors.lastname: Jiang
authors.forename: Jing
authors.initials: J
authors.lastname: Qi
authors.forename: Xugang
authors.initials: X
authors.lastname: Li
authors.forename: Klaus
authors.initials: K
authors.lastname: Palme
authors.forename: Chuanyou
authors.initials: C
authors.lastname: Li
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000254:growth & development; D054883:Oxylipins / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development*; D011401:Promoter Regions, Genetic; D055153:Stem Cell Niche; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003517:Cyclopentanes; D007210:Indoleacetic Acids; C473611:MYC2 protein, Arabidopsis; D054883:Oxylipins; C493246:PLT1 protein, Arabidopsis; C493247:PLT2 protein, Arabidopsis; D010937:Plant Growth Regulators; D014157:Transcription Factors; C011006:jasmonic acid