Dr Jo HepworthVisiting Scientist Genes in the Environment
Jo is a plant geneticist with a passion for understanding how plants coordinate their growth with their environment.
As part of the BRAVO project, lead by Prof. Lars Ostergaard and project-managed by Rachel Wells, Jo is investigating how vernalisation (the process in which plants register winter, so that they flower faster in spring) affects flowering time and branching in the subsequent inflorescence in Brassicas, particularly rapeseed.
She started working on vernalisation in Prof. Caroline Dean’s group, which works on the genetic mechanisms underlying flowering time control, particularly at the key floral repressor FLOWERING LOCUS C (FLC). FLC is a major regulator of development in Arabidopsis thaliana, as its expression determines the life history of the plant by controlling the timing of the transition to flowering. FLC expression must be repressed by experiencing winter before flowering can occur.
However, although vernalisation allows plants to synchronise flowering with the end of winter, how do plants identify “winter”? In the field during autumn and winter temperatures can span twenty degrees daily, more than the difference between autumn and winter.
By working closely with Dr Rea Antoniou Kourounioti in Professor Martin Howard’s group, and running experiments both in the lab and the field, Jo exploited the FLC system to determine how organisms can measure and integrate temperature information to accurately recognise the passing seasons.
But although Arabidopsis has 1 copy of FLC, Brassica crops have many, due to several cycles of whole-genome duplication. Brassica napus (oilseed rape) has at least 9 copies – how do these interact? And how do they continue to affect the inflorescence the plant has produced long after winter has passed? Jo works with Dr Alex Calderwood in Prof. Richard Morris’s group and collaborates with the team at the National Phenomics Platform, Aberystwyth, using state-of-the-art plant imaging and old-fashioned genetics to identify how differences in FLC and other genes result in a beautiful diversity of plant forms and responds to winter.
Hepworth J,Antoniou-Kourounioti RL,Berggren K,Selga C,Tudor EH,Yates B,Cox D,Collier Harris B,Irwin JA,Howard M,Säll T,Holm S,Dean C (2020)Natural variation in autumn expression is the major adaptive determinant distinguishing Arabidopsis FLC haplotypes.eLife (9)Publisher's version: 2050-084X
Antoniou-Kourounioti R. L., Hepworth J., Heckmann A., Duncan S., Qüesta J., Rosa S., Säll T., Holm S., Dean C., Howard M. (2018)Temperature sensing is distributed throughout the regulatory network that controls FLC epigenetic silencing in vernalizationCell Systems (7)Publisher's version: 2405-4712
Hepworth J., Antoniou-Kourounioti R. L., Bloomer R. H., Selga C., Berggren K., Cox D., Collier Harris B. R., Irwin J. A., Holm S., Säll T., Howard M., Dean C. (2018)Absence of warmth permits epigenetic memory of winter in Arabidopsis.Nature communications (9)Publisher's version: 2041-1723