title: TIME FOR COFFEE controls root meristem size by changes in auxin accumulation in Arabidopsis.
abstract: Roots play important roles in plant survival and productivity as they not only anchor the plants in the soil but are also the primary organ for the uptake of nutrients from the outside. The growth and development of roots depend on the specification and maintenance of the root meristem. Here, we report a previously unknown role of TIME FOR COFFEE (TIC) in controlling root meristem size in Arabidopsis. The results showed that loss of function of TIC reduced root meristem length and cell number by decreasing the competence of meristematic cells to divide. This was due to the repressed expression of PIN genes for decreased acropetal auxin transport in tic-2, leading to low auxin accumulation in the roots responsible for reduced root meristem, which was verified by exogenous application of indole-3-acetic acid. Downregulated expression of PLETHORA1 (PLT1) and PLT2, key transcription factors in mediating the patterning of the root stem cell niche, was also assayed in tic-2. Similar results were obtained with tic-2 and wild-type plants at either dawn or dusk. We also suggested that the MYC2-mediated jasmonic acid signalling pathway may not be involved in the regulation of TIC in controlling the root meristem. Taken together, these results suggest that TIC functions in an auxin-PLTs loop for maintenance of post-embryonic root meristem.
authors.affiliation: College of Life Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Hong
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Yan
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Liu
authors.forename: Hong-Guo
authors.initials: HG
authors.lastname: Chen
authors.forename: Ying-Tang
authors.initials: YT
authors.lastname: Lu
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002452:Cell Count; D048429:Cell Size; D057906:Circadian Clocks; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D030821:Plants, Genetically Modified; D015398:Signal Transduction; 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; D009687:Nuclear Proteins; D054883:Oxylipins; C493246:PLT1 protein, Arabidopsis; C493247:PLT2 protein, Arabidopsis; C523534:TIC protein, Arabidopsis; D014157:Transcription Factors; C011006:jasmonic acid; C030737:indoleacetic acid
keywords: Arabidopsis thaliana; MYC2; PIN; TIME FOR COFFEE.; auxin; circadian clock; jasmonic acid; root meristem