title: Ectopic expression of the Arabidopsis MINI ZINC FINGER1 and MIF3 genes induces shoot meristems on leaf margins.
abstract: A leaf undergoes determinate growth from a primordium on flank of the shoot apical meristem. Several intrinsic pathways restrict meristematic activity in the leaf of Arabidopsis; however, other factors remain to be defined. We report here that the overexpression of MINI ZINC FINGER1 (MIF1) or MIF3 disrupted the leaf determinate growth by inducing ectopic shoot meristems on leaf margins. These ectopic meristems occurred along margins of late rosette leaves at serration sinuses in an ERECTA-dependent manner. Expression of STM was activated in these ectopic meristems but not other leaf regions. The formation of ectopic meristems was independent of the BP gene but suppressed by exogenous gibberellic acid. In addition, reduced auxin response along leaf margins and subsequent response peak in the sinus were correlated with the occurrence of ectopic meristems. Our results suggest that the sinus of leaf serration is a quiescent domain possessing the potential for meristem formation. MIF1- or MIF3-overexpressing transgenic plants may provide a new genetic system for dissecting the molecular mechanism that maintains leaf determinate growth, and for understanding the interactions between hormone actions and meristematic activity.
authors: Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.
authors: Wei
authors: W
authors: Hu
authors: Baomin
authors: B
authors: Feng
authors: Hong
authors: H
authors: Ma
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins; D035264:Flowers / Q000235:genetics / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics; D018519:Meristem / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C405985:Knox1 protein, plant; C509082:MIF1 protein, Arabidopsis; C509084:MIF3 protein, Arabidopsis; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C097496:STM protein, Arabidopsis; C457763:ER protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases