Activation of the WUS gene induces ectopic initiation of floral meristems on mature stem surface in Arabidopsis thaliana.
A gain-of-function Arabidopsis mutant was identified via activation tagging genetic screening. The mutant exhibited clustered ectopic floral buds on the surface of inflorescence stems. The mutant was designated as sef for stem ectopic flowers. Our detailed studies indicate that the ectopic flower meristems are initiated from the differentiated cortex cells. Inverse PCR and sequence analysis indicated that the enhancer-containing T-DNA from the activation tagging construct, SKI015, was inserted upstream of the previously cloned WUS gene encoding a homeodomain protein. Studies from RT-PCR, RNA in situ hybridization and transgenic plant analysis further confirmed that the phenotypes of sef are caused by the overexpression of WUS. Our results suggest that overexpression of WUS could trigger the cell pluripotence and reestablish a new meristem in cortex. The type of new meristems caused by WUS overexpression was dependent upon the developmental and physiological stages of a plant. With the help of some undefined factors in the reproductive organs the new meristems differentiated into floral buds. In a vegetative growth plant, however, only the new vegetative buds can be initiated upon the overexpression of WUS. These studies provide new insights of WUS on flower development.
Xu
Yun-Yuan
YY
Key Laboratory of Photosynthesis & Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, XiangShan, Beijing, 100093, China.
Wang
Xiao-Min
XM
Li
Jia
J
Li
Jun-Hua
JH
Wu
Jin-Song
JS
Walker
John C
JC
Xu
Zhi-Hong
ZH
Chong
Kang
K
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics*; D004958:Estradiol / Q000494:pharmacology; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D010641:Phenotype; D035261:Plant Components, Aerial / Q000235:genetics / Q000254:growth & development*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; C074747:LFY protein, Arabidopsis; D012333:RNA, Messenger; D014157:Transcription Factors; C116421:WUSCHEL protein, Arabidopsis; D004958:Estradiol