title: Pattern of auxin and cytokinin responses for shoot meristem induction results from the regulation of cytokinin biosynthesis by AUXIN RESPONSE FACTOR3.
abstract: De novo organ regeneration is an excellent biological system for the study of fundamental questions regarding stem cell initiation, cell fate determination, and hormone signaling. Despite the general belief that auxin and cytokinin responses interact to regulate de novo organ regeneration, the molecular mechanisms underlying such a cross talk are little understood. Here, we show that spatiotemporal biosynthesis and polar transport resulted in local auxin distribution in Arabidopsis (Arabidopsis thaliana), which in turn determined the cytokinin response during de novo shoot regeneration. Genetic and pharmacological interference of auxin distribution disrupted the cytokinin response and ATP/ADP ISOPENTENYLTRANSFERASE5 (AtIPT5) expression, affecting stem cell initiation and meristem formation. Transcriptomic data suggested that AUXIN RESPONSE FACTOR3 (ARF3) mediated the auxin response during de novo organ regeneration. Indeed, mutations in ARF3 caused ectopic cytokinin biosynthesis via the misexpression of AtIPT5, and this disrupted organ regeneration. We further showed that ARF3 directly bound to the promoter of AtIPT5 and negatively regulated AtIPT5 expression. The results from this study thus revealed an auxin-cytokinin cross talk mechanism involving distinct intermediate signaling components required for de novo stem cell initiation and shed new light on the mechanisms of organogenesis in planta.
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
authors.forename: Zhi Juan
authors.initials: ZJ
authors.lastname: Cheng
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Zhou
authors.forename: Ying Hua
authors.initials: YH
authors.lastname: Su
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Tian Tian
authors.initials: TT
authors.lastname: Sun
authors.forename: Xiang Yu
authors.initials: XY
authors.lastname: Zhao
authors.forename: Xing Guo
authors.initials: XG
authors.lastname: Li
authors.forename: Youfa
authors.initials: Y
authors.lastname: Cheng
authors.forename: Yunde
authors.initials: Y
authors.lastname: Zhao
authors.forename: Qi
authors.initials: Q
authors.lastname: Xie
authors.forename: Xian Sheng
authors.initials: XS
authors.lastname: Zhang
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D047369:Chromatin Immunoprecipitation; D003583:Cytokinins / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D059828:Plant Cells / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D004268:DNA-Binding Proteins; C109765:ETT protein, Arabidopsis; D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; D009687:Nuclear Proteins; C116421:WUSCHEL protein, Arabidopsis; D019883:Alkyl and Aryl Transferases; C024274:adenylate isopentenyltransferase