Molecular characterization of vernalization loci VRN1 in wild and cultivated wheats

Sequence analysis indicated great variability in the region from -62 to -221 nucleotide positions of the VRN1 promoter region. Different indels were found within this region in spring wheats. It was shown that VRN1 promoter region of B and G genome can also contain damages such as the insertion of the transposable element.Some transcription factor recognition sites including hybrid C/G-box for TaFDL2 protein known as the VRN1 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.We can conclude that supposed molecular mechanism of the VRN1 gene activating in cultivated diploid wheat species T. monococcum is common also for wild T. boeoticum and was inherited by T. monococcum. The spring polyploids are not related in their origin to spring diploids. The spring T. urartu and goatgrass accessions have another mechanism of flowering activation that is not connected with indels in VRN1 promoter region. All obtained data may be useful for detailed insight into origin of spring wheat forms in evolution and domestication process.Some plants of middle latitudes require vernalization treatment (a long exposure to low temperatures) to induce their flowering. This adaptation appeared to protect flower from destruction by cold temperature during winter. Besides being an important trait for adaptation, the requirement of vernalization is also of a great agronomical importance. In crops such as common wheat (Triticum aestivum L.), a vernalization requirement distinguishes winter varieties from spring ones. Spring growth habit is a potential advantage in cold climates, with short vegetation season and cold winter, for agriculture which main task is to achieve rich harvest. In continental middle latitud