Molecular characterization of vernalization loci VRN1 in wild and cultivated wheats

<p>Abstract</p> <p>Background</p> <p>Variability of the <it>VRN1 </it>promoter region of the unique collection of spring polyploid and wild diploid wheat species together with diploid goatgrasses (donor of B and D genomes of polyploid wheats) were investigated. Accessions of wild diploid (<it>T. boeoticum</it>, <it>T. urartu</it>) and tetraploid (<it>T. araraticum, T. timopheevii</it>) species were studied for the first time.</p> <p>Results</p> <p>Sequence analysis indicated great variability in the region from -62 to -221 nucleotide positions of the <it>VRN1 </it>promoter region. Different indels were found within this region in spring wheats. It was shown that <it>VRN1 </it>promoter region of B and G genome can also contain damages such as the insertion of the transposable element.</p> <p>Some transcription factor recognition sites including hybrid C/G-box for TaFDL2 protein known as the <it>VRN1 </it>gene upregulator were predicted inside the variable region. It was shown that deletions leading to promoter damage occurred in diploid and polyploid species independently. DNA transposon insertions first occurred in polyploid species. At the same time, the duplication of the promoter region was observed in A genomes of polyploid species.</p> <p>Conclusions</p> <p>We can conclude that supposed molecular mechanism of the <it>VRN1 </it>gene activating in cultivated diploid wheat species <it>T. monococcum </it>is common also for wild <it>T. boeoticum </it>and was inherited by <it>T. monococcum</it>. The spring polyploids are not related in their origin to spring diploids. The spring <it>T. urartu </it>and goatgrass accessions have another mechanism of flowering activation that is not connected with indels in <it>VRN1 </it>promoter region. All obtained data may be useful for detailed insight into origin of spring wheat forms in evolution and domestication process.</p