title: A new loss-of-function allele 28y reveals a role of ARGONAUTE1 in limiting asymmetric division of stomatal lineage ground cell.
abstract: In Arabidopsis thaliana L., stomata are produced through a series of divisions including asymmetric and symmetric divisions. Asymmetric entry division of meristemoid mother cell produces two daughter cells, the smaller meristemoid and the larger sister cell, a stomatal lineage ground cell (SLGC). Stomatal lineage ground cells can differentiate into epidermal pavement cells but have the potential to divide asymmetrically, spacing divisions, to create satellite meristemoids. Peptide ligands and TOO MANY MOUTHS (TMM) and ERECTA family receptors regulate the initiation of stomatal lineages, activity, and orientation of spacing divisions. Here, we reported that a natural mutant 28y displayed an increased stomatal density and index. Using map-based cloning, we identified mutation in ARGONAUTE1 (AGO1) as the cause of 28y phenotypes. Time-lapse tracing of stomatal lineage cells reveals that stomatal overproduction in 28y is caused by the excessive asymmetric spacing division of SLGCs. Further genetic results demonstrated that AGO1 acts downstream of TMM and negatively regulates the SPCH transcripts, but in a brassinosteroid-independent manner. Upregulation of AGAMOUS-LIKE16 (AGL16) in 28y mutants suggests that AGO1 is required to restrict AGL16-mediated stomatal spacing divisions, an miRNA pathway in addition to ligand-receptor signaling modules.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Kezhen
authors.initials: K
authors.lastname: Yang
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.forename: Jie
authors.initials: J
authors.lastname: Le
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060565:Argonaute Proteins / Q000235:genetics* / Q000378:metabolism; D060049:Asymmetric Cell Division / Q000187:drug effects; D060406:Brassinosteroids / Q000494:pharmacology; D019070:Cell Lineage / Q000187:drug effects; D018548:Cotyledon / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004843:Epistasis, Genetic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D018546:Hypocotyl / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D054046:Plant Stomata / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D060406:Brassinosteroids; D035683:MicroRNAs; D012333:RNA, Messenger
keywords: ARGONAUTE1; Arabidopsis; cell division; stomatal development