profile avatar

Transcription of the VERNALIZATION1 gene (VRN1) is induced by prolonged cold (vernalization) to trigger flowering of cereal crops, such as wheat and barley. VRN1 encodes a MADS box transcription factor that promotes flowering by regulating the expression of other genes. Here we use transcriptome sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) to identify direct targets of VRN1. Over 500 genomic regions were identified as potential VRN1-binding targets by ChIP-seq. VRN1 binds the promoter of FLOWERING LOCUS T-like 1, a promoter of flowering in vernalized plants. VRN1 also targets VERNALIZATION2 and ODDSOC2, repressors of flowering that are downregulated in vernalized plants. RNA-seq identified additional VRN1 targets that might play roles in triggering flowering. Other targets of VRN1 include genes that play central roles in low-temperature-induced freezing tolerance, spike architecture and hormone metabolism. This provides evidence for direct regulatory links between the vernalization response pathway and other important traits in cereal crops.


Epitope-tagged VRN1 protein accelerates flowering of barley

A transgene construct was designed to express the barley VERNALIZATION1 protein (VRN1) fused to six copies of the haemagglutinin epitope tag (amino acid sequence YPYDVPDYA). The VRN1-HA gene construct was derived from the genomic sequence of VRN1, is driven by the endogenous promoter and has the 3′ UTR of VRN1, but lacks most of the large first intron (Fig. 1a). This construct was transformed into the cultivar Golden Promise, a spring barley amenable to Agrobacterium transformation. Transgenic barley plants that carry the VRN1-HA construct flowered earlier than either wild-type parent line or sibling null lines, which were descended from the same transformation events but did not inherit the transgene (Fig. 1b–d and Supplementary Fig. 1). The earliest flowering lines expressing the VRN1-


ارسال یک دیدگاه