title: Control of root meristem size by DA1-RELATED PROTEIN2 in Arabidopsis.
abstract: The control of organ growth by coordinating cell proliferation and differentiation is a fundamental developmental process. In plants, postembryonic root growth is sustained by the root meristem. For maintenance of root meristem size, the rate of cell differentiation must equal the rate of cell division. Cytokinin and auxin interact to affect the cell proliferation and differentiation balance and thus control root meristem size. However, the genetic and molecular mechanisms that determine root meristem size still remain largely unknown. Here, we report that da1-related protein2 (dar2) mutants produce small root meristems due to decreased cell division and early cell differentiation in the root meristem of Arabidopsis (Arabidopsis thaliana). dar2 mutants also exhibit reduced stem cell niche activity in the root meristem. DAR2 encodes a Lin-11, Isl-1, and Mec-3 domain-containing protein and shows an expression peak in the border between the transition zone and the elongation zone. Genetic analyses show that DAR2 functions downstream of cytokinin and SHORT HYPOCOTYL2 to maintain normal auxin distribution by influencing auxin transport. Further results indicate that DAR2 acts through the PLETHORA pathway to influence root stem cell niche activity and therefore control root meristem size. Collectively, our findings identify the role of DAR2 in root meristem size control and provide a novel link between several key regulators influencing root meristem size.
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yuancheng
authors.initials: Y
authors.lastname: Peng
authors.forename: Wenying
authors.initials: W
authors.lastname: Ma
authors.forename: Liangliang
authors.initials: L
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Shengjun
authors.initials: S
authors.lastname: Li
authors.forename: Hongtao
authors.initials: H
authors.lastname: Zhao
authors.forename: Yankun
authors.initials: Y
authors.lastname: Zhao
authors.forename: Weihuan
authors.initials: W
authors.lastname: Jin
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Michael W
authors.initials: MW
authors.lastname: Bevan
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Yiping
authors.initials: Y
authors.lastname: Tong
authors.forename: Yunhai
authors.initials: Y
authors.lastname: Li
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology* / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003583:Cytokinins / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000494:pharmacology; D018519:Meristem / Q000033:anatomy & histology* / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009929:Organ Size / Q000187:drug effects; D055153:Stem Cell Niche / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; C582826:DA1-related protein 2, Arabidopsis; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids