Dormancy and vernalization protect plants against winter conditions and enable flowering in the spring.
However, climate change is disrupting the environmental signals required for dormancy and vernalization and altering plant's life cycle in ecosystems and agriculture. This multidisciplinary project combines genomics, epigenetics, molecular and computational biology to untangle the molecular links between dormancy and vernalization in raspberry, Rubus idaeus L. This project involves fundamental and applied research which will be translated into R. idaeus. Raspberry offers a great model for dormancy studies due to its short life cycle and small genome size.
VERNALIZATION 1 (VRN1) mediates the transition to flowering in response to cold in Arabidopsis by regulating FLOWERING LOCUS C (FLC) and FLOWERING TIME (FT). My group identified a mutation in a VRN1-like gene from raspberry (RiVRN1.1 allele) that misregulates dormancy induction.
The mutants display active growth and flowering during the winter (Mateos et al., 2024).
RiVRN1.1 could be a key genetic resource for the raspberry industry, allowing to bypass dormancy and flower all year and enhancing resilience in warmer climates. Aim: Characterizing the molecular mechanisms underlying the phenotype of RiVRN1.1 mutants as source of environment-independent flowering in raspberry (R. idaeus). 1.
Identifying the molecular target of RiVRN1.1.We hypothesize that raspberry VRN1 acts within FLC and FT flowering pathway, and that the expression of these genes is misregulated in RiVRN1.1 mutant raspberry plants. Since there are multiple FT-like and FLC-like genes in the raspberry genome, the project will start by screening the in-house Rubus reference transcriptome for FLC and FT as potential targets of RiVRN1.1.
As VRN1 is a known transcription factor, RiVRN1 will be co-expressed in Nicotiana tabacum with constructs expressing a reporter under the promoter of the candidate genes. The results will be complemented with DAP-seq in Rubus, to identify candidate targets of RiVRN1.1 (Bartlett et al., 2017).
14 VRN1-like genes of Rubus differentially expressed during dormancy will be further explored by heterologous expression in Arabidopsis.
Their flowering phenotypes will be characterised, as well as the expression profile of downstream elements of the vernalization pathway.2.
Understanding the mechanism of action of RiVRN1.1 in dormancy.In model species VRN1 participates in the repression of FLC through Histone3 lysine27 tri-methylation (H3K27me3) – a reversible epigenetic mark.
This mechanism will be investigated in Rubus through H3K27me3 chromatin immunoprecipitation (ChIP) in wild type and RiVRN1.1 mutants.
As contingency plan, repressive epigenetic marks such as DNA methylation could be explored.The EastBio partnership offers fully-funded competition based studentships.
Funding covers Home (UK fees), a stipend at UKRI norm level (£19,327 for 2024/2025) and project costs.
Application guidance can be found on the Eastbio website; How to Apply ¦ Biology.
Information on UKRI-BBSRC can be found on the UKRI website UKRI – UK Research and Innovation