Targeted epigenetic modifications to engineer novel traits in plants

Lead Research Organisation: University of Warwick
Department Name: School of Life Sciences

Abstract

The eukaryotic epigenome has a fundamental role in determining and maintaining cell identity and function. Recently, epigenome editing techniques based on the CRISPR-Cas9 system have been reported to directly manipulate specific modifications at precise genomic regions. However, the number of editable modifications as well as studies applying these techniques in vivo is still limited.

To address this my PhD project will be focused on designing tools and techniques able to achieve artificial modification in plants at the epigenetic level. The first approach that will be taken will consist in testing fusion proteins of catalytically inactive Cas9 (dCas9) with either methylating or demethylating enzymes in order to alter DNA methylation marks in a programmable target region specific manner. These constructs will be tested with a luciferase reporter system first in Arabidopsis thaliana's protoplasts and when optimised, in crops such as tomato and maize.

Along with the two-parts protein fusion complex a SUNTAG system will be used where the dCas9 protein is fused to repetitive peptide epitopes that are able to recruit multiple copies of the chosen enzyme and it could allow the amplification of the modifying effect in the genomic sites of interest.

Were these systems been proven effective it will be possible to use them to induce specific changes in chromatin architecture as well, by modifying the states of the histones tails and therefore the regulatory activity of targeted gene enhancers with high specificity. This may allow the modulation of developmental genes in specific contexts by either activating or inactivating their specific enhancers.

Collectively, these techniques might allow modifications of heritable epigenetic marks that could result in heritable phenotypic variation. This could be exploited to improve important agronomic traits, such as respiration, energy-use efficiency, yield components and seed quality, thus offering practical perspectives for breeders.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M01116X/1 01/10/2015 30/09/2023
2097338 Studentship BB/M01116X/1 01/10/2018 30/09/2022 Lorenzo Pellegrini