title: Cytokinin-mediated cell cycling arrest of pericycle founder cells in lateral root initiation of Arabidopsis.
abstract: In Arabidopsis, lateral root formation is a post-embryonic developmental event, which is regulated by hormones and environmental signals. In this study, via analyzing the expression of cyclin genes during lateral root (LR) formation, we report that cytokinins (CTKs) inhibit the initiation of LR through blocking the pericycle founder cells cycling at the G(2) to M transition phase, while the promotion by CTK of LR elongation is due to the stimulation of the G(1) to S transition. No significant difference was detected in the inhibitory effect of CTK on LR formation between wild-type plants and mutants defective in auxin response or transport. In addition, exogenously applied auxin at different concentrations could not rescue the CTK-mediated inhibition of LR initiation. Our data suggest that CTK and auxin might control LR initiation through two separate signaling pathways in Arabidopsis. The CTK-mediated repression of LR initiation is transmitted through the two-component signal system and mediated by the receptor CRE1.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zi Jin Gang Campus, Zhejiang University, Hangzhou, 310058, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Mo
authors.forename: Huixia
authors.initials: H
authors.lastname: Shou
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000502:physiology; D002453:Cell Cycle / Q000187:drug effects* / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D003583:Cytokinins / Q000494:pharmacology*; D016195:G2 Phase / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000502:physiology; D011494:Protein Kinases / Q000502:physiology; D011956:Receptors, Cell Surface / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D007210:Indoleacetic Acids; D011956:Receptors, Cell Surface; D011494:Protein Kinases; C421783:WOL protein, Arabidopsis