VERNALIZATION2 alters early tiller development in a facultative spring hexaploid bread wheat

Area of Science:

• Plant Science
• Genetics
• Agricultural Science

Background:

• Vernalization is crucial for winter cereal flowering time, regulated by the VERNALIZATION2 (VRN2) gene.
• The VRN2 locus in hexaploid bread wheat (Triticum aestivum) is not well understood, especially in facultative spring types.

Purpose of the Study:

• To investigate the subgenomic regulation and function of the VRN2 locus in facultative spring hexaploid wheat.
• To differentiate gene expression and phenotypic traits at the VRN2 locus under simulated UK field conditions.

Main Methods:

• Generated defined germplasm of hexaploid bread wheat.
• Developed bespoke experimental protocols to simulate annual UK field conditions.
• Analyzed gene expression and phenotypic differences at the VRN2 locus.

Main Results:

• Identified that VRN2 locus genes, ZCCT1 and ZCCT2, exhibit differential expression patterns influenced by multiple environmental factors.
• Discovered coregulation between ZCCT-D1 and ZCCT-D2, forming a regulatory loop.
• Found that VRN-D2 influences early tiller development, including accelerated secondary tiller emergence and coleoptile tillers.

Conclusions:

• The VRN2 locus in bread wheat comprises multiple genes with both overlapping and unique regulatory and functional roles.
• Targeting individual VRN2 genes presents a potential strategy for altering wheat plant architecture independently of vernalization requirements.