2026/04/01 by Beáta Strejčková, Zbyněk Milec, Tereza Šlajsová +6 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Plant Molecular Biology Research #Plant Reproductive Biology #Wheat and Barley Genetics and Pathology
paper · pdf · doi:10.1007/s11032-026-01657-6
openalex publication_date 2026/04/01 · openalex created_date 2026/04/10 · openalex updated_date 2026/07/29
Abstract In temperate cereals, vernalization regulates the transition from vegetative to reproductive growth in response to low temperatures. A central component of this pathway is VERNALIZATION 1 ( VRN1 ). In winter wheat cultivars, the recessive vrn1 allele is transcriptionally activated by cold and promotes the transition to flowering. In contrast, spring cultivars carry dominant VRN1 alleles expressed in a cold-independent manner. This is caused by mutations in the cis -regulatory elements in the promoter or in the “critical region” of intron 1. The widespread spring bread wheat allele Vrn-A1a carries a promoter mutation but retains a winter-like allele intron 1. Intriguingly, Vrn-A1a is partially responsive to cold, suggesting regulatory element(s) beyond the promoter mutation. Here, we investigated the effect of combined promoter and first intron mutations on Vrn-A1a expression and flowering time in bread wheat. We deleted a 901-bp segment of the Vrn-A1a so-called “critical region”, thus generating a novel combination of the promoter and intron 1 mutations not found in natural germplasm. Plants carrying both mutations exhibited Vrn-A1 transcript levels and flowering times comparable to those of the wild-type under both vernalizing and non-vernalizing conditions. Hence, partial cold responsiveness of Vrn-A1a is controlled by regulatory element(s) outside the removed intron 1 segment. Overall, our study advances the understanding of VRN1 transcriptional regulation and highlights the complexity of vernalization control in wheat.