Olivia Nippe
Research Overview
My area of interest concerns the role of biological rhythms in plants, specifically the identification and characterisation of microbial effectors interfering with the plant circadian rhythm.
Infection of economically important crops by rapidly evolving pathogenic bacteria poses an on-going threat to food security, often causing substantial loss to crop yields. The delivery of virulence factors from certain pathogens to the host via Type III Secretion systems can enable key components of the plant’s immune system to be targeted using a range of effector proteins. These effectors are crucial to pathogens whose presence cannot be overlooked by the host. Subsequently, plants have evolved a number of receptors capable of recognising these effectors, leading to an evolutionary arms race between pathogen and host [1]. One mediator of the Arabidopsis defence response is the circadian clock, which regulates the expression levels of immune receptors in a temporal fashion, as well as stomatal aperture, which has recently been proven as an active way for the innate immune system to limit bacterial entry[2][3]. Such rhythmicity enables organisms to maximise efficiency through synchronisation with their environment. The plant’s circadian oscillator is therefore a likely target for bacterial effectors.
The aim of this project is to identify Pseudomonas syringae effectors that are targeting the Arabidopsis circadian clock, and characterise the molecular mechanisms underlying their virulence. It is our hope that characterisation of the mechanism employed by these effectors will permit the engineering of more disease resistant crops, as well as generate synthetic tools that can be used to manipulate the clock to the advantage of plant fitness.
References:
[1] Büttner, D. et al., 2016. Behind the lines-actions of bacterial type III effector proteins in plant cells. FEMS microbiology reviews, 103(1), pp.60–69.
[2] Zhang, C. et al., 2013. Crosstalk between the Circadian Clock and Innate Immunity in Arabidopsis F. M. Ausubel, ed. PLoS Pathogens, 9(6), p.e1003370.
[3] Wang, W. et al., 2011. Timing of plant immune responses by a central circadian regulator. Nature, 470(7332), pp.110–114.
Olivia is currently pursuing a PhD in Life Sciences at the University of Warwick, and is in her third year of the MIBTP Doctoral Training Programme studying microbial effectors interfering with the plant circadian rhythm in the Ntoukakis lab.
