RRC ID 3896
Author Shimada S, Ogawa T, Kitagawa S, Suzuki T, Ikari C, Shitsukawa N, Abe T, Kawahigashi H, Kikuchi R, Handa H, Murai K.
Title A genetic network of flowering-time genes in wheat leaves, in which an APETALA1/FRUITFULL-like gene, VRN1, is upstream of FLOWERING LOCUS T.
Journal Plant J.
Abstract To elucidate the genetic mechanism of flowering in wheat, we performed expression, mutant and transgenic studies of flowering-time genes. A diurnal expression analysis revealed that a flowering activator VRN1, an APETALA1/FRUITFULL homolog in wheat, was expressed in a rhythmic manner in leaves under both long-day (LD) and short-day (SD) conditions. Under LD conditions, the upregulation of VRN1 during the light period was followed by the accumulation of FLOWERING LOCUS T (FT) transcripts. Furthermore, FT was not expressed in a maintained vegetative phase (mvp) mutant of einkorn wheat (Triticum monococcum), which has null alleles of VRN1, and never transits from the vegetative to the reproductive phase. These results suggest that VRN1 is upstream of FT and upregulates the FT expression under LD conditions. The overexpression of FT in a transgenic bread wheat (Triticum aestivum) caused extremely early heading with the upregulation of VRN1 and the downregulation of VRN2, a putative repressor gene of VRN1. These results suggest that in the transgenic plant, FT suppresses VRN2 expression, leading to an increase in VRN1 expression. Based on these results, we present a model for a genetic network of flowering-time genes in wheat leaves, in which VRN1 is upstream of FT with a positive feedback loop through VRN2. The mvp mutant has a null allele of VRN2, as well as of VRN1, because it was obtained from a spring einkorn wheat strain lacking VRN2. The fact that FT is not expressed in the mvp mutant supports the present model.
Volume 58(4)
Pages 668-81
Published 2009-5
DOI 10.1111/j.1365-313X.2009.03806.x
PMID 19175767
PMC PMC2721963
MeSH Cloning, Molecular Flowers / genetics Flowers / growth & development Flowers / metabolism Gene Expression Regulation, Plant Gene Regulatory Networks Genes, Plant MADS Domain Proteins / genetics MADS Domain Proteins / metabolism* Phylogeny Plant Leaves / genetics* Plant Leaves / metabolism Plant Proteins / genetics Plant Proteins / metabolism* Plants, Genetically Modified / genetics Plants, Genetically Modified / metabolism RNA, Plant / genetics Triticum / genetics* Triticum / metabolism
IF 5.726
Times Cited 72
Wheat LPGKU2269(Chinese Spring) KU-104-2 KT10-1? (EST) database