Axillary meristem development in the branchless Zu-0 ecotype of Arabidopsis thaliana.
Axillary meristems form in the leaf axils during post-embryonic development. In order to initiate the genetic dissection of axillary meristem development, we have characterized the late-flowering branchless ecotype of Arabidopsis thaliana (L.) Heynh., Zu-0. The first-formed rosette leaves of Zu-0 plants all initiate axillary meristems, but later-formed leaves of the rosette remain branchless. Alteration in the meristem development is axillary meristem-specific because the shoot apical and floral meristems develop normally. Scanning electron microscopy, histology and RNA in situ analysis with SHOOTMERISTEMLESS ( STM), a marker for meristematic tissues, show that a mound of cells form and STM mRNA accumulates in barren leaf axils, indicating that axillary meristems initiate but arrest in their development prior to organizing a meristem proper. Expression and retention of the STM RNA in barren leaf axils further suggests that STM expression is not sufficient for the establishment of the axillary meristem proper.
Kalinina
Anna
A
Department of Plant Sciences, University of Western Ontario, London, Canada.
Mihajlović
Nela
N
Grbić
Vojislava
V
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005819:Genetic Markers; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D018519:Meristem / Q000254:growth & development* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D010641:Phenotype; D018515:Plant Leaves / Q000254:growth & development*; D018547:Plant Stems / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D005819:Genetic Markers; D018398:Homeodomain Proteins; D012333:RNA, Messenger; C097496:STM protein, Arabidopsis