In a changing climate, it will become an increasing challenge to ensure food security. A contributing factor to this is that cereals are highly sensitive to the more irregular and extreme temperatures. The environmental factors temperature and photoperiod are key regulators of the transition from vegetative to floral growth.

This is an essential transition which needs to be timed correctly to optimise reproductive success and is critical for high crop yields. For cereals which experience a winter growth habit, the extended period of cold exposure called vernalization is essential for floral transition to occur. The cereal-specific floral repressor VERNALIZATION2 (VRN2) has an integral role in this pathway, yet this locus remains poorly characterised in hexaploid wheat.

Our research suggests that the tandemly duplicated genes comprising the VRN2 locus, ZCCT1 and ZCCT2, show differences in gene expression patterns in varying environmental conditions at both a gene and subgenome level. Additionally, interactions between each ZCCT protein and the key floral promoter VERNALIZATION1 (VRN1), alongside interactions with their promoter regions, provide new insight into the vernalization network.

Different allelic variants of VRN1 and VRN2 have also been analysed based on selection occurring in the ‘Watkins’ collection comprised of landraces from across the globe, with further testing of protein interactions between these variants showing further specificity. The differing response to extreme cold temperatures across a panel of these diverse ‘Watkins’ landrace varieties also indicate that VRN2 has a role in cold stress in addition to vernalization response.

Continuing to further our understanding of VRN2 will enable the generation of more temperature-robust wheat varieties, essential to ensure high yields with a changing climate.