Project No. 2315

PRIORITY PROJECT

Primary Supervisor

Dr Helen Cockerton – University of Kent

Co-Supervisor(s)

Prof Alessia Buscaino – University of Kent

Prof Xiangming Xu – NIAB at East Malling

Dr Andrew Armitage – University of Greenwich

Summary

Rational: Plant pathogens can cause extensive damage to crops, and if left untreated, outbreaks can lead to complete crop destruction.

New biotechnologies such as Host Induced Gene Silencing (HIGS) can be used to provide an environmentally friendly strategy for disease control. Here we ask whether RNA interference (RNAi) mediated by hairpins can boost baseline plant immunity or whether targeted hairpins are required to generate disease resistant plants.

Published work has shown that exogenous application of random small interfering RNA (siRNA) can create disease resistant plants through the upregulation of pathogen triggered immunity. Preliminary data suggests that “internally generated” siRNA produced through the introduction of a hairpin can also upregulate a plants baseline immunity, irrespective of the hairpin target. Here we will study whether the introduction of an off-target RNAi hairpin can generate disease resistant plants.

Approaches:

WP1: The student will transform the model plant Arabidopsis thaliana to contain HIGS constructs. Multiple transformation lines will be produced, these will target 1) control genes (not present in the plant or the pathogen) 2) pathogenicity genes present in the target fungal pathogen 3) an empty control vector that does not contain a hairpin.

WP2: The student will then conduct disease assays on the resulting Arabidopsis thaliana HIGS lines to assess disease resistance status to Alternaria, Hyaloperonospora, Pseudomonas and Verticillium pathogens.

WP3: RNA sequencing of controlled infection of HIGS Arabidopsis thaliana lines will be used to identify potential upregulation of pathogen triggered immunity genes. Pre-existing lines exhibiting universal resistance will be assessed if new lines are not found.

Impact: This project will inform the impact of “off-target” HIGS on a plants base line immunity. Ultimately, the project will shed light on whether there is a secondary mechanism of resistance created by the use of RNA hairpins to reveal an underexploited mechanism of disease resistance.