Ms Brenda Salasini
Biochemistry, Genetics and Microbiology
IDENTIFICATION AND IN PLANTA FUNCTIONAL ANALYSES OF RxLR EFFECTORS OF THE OOMYCETE PHYTOPHTHORA PARASITICA
The oomycete genus Phytophthora represents plant destroyers that cause devastating diseases on agricultural crops and plants in diverse ecosystems (Erwin and Ribeiro, 1996). To establish infection, adapted Phytophthora species employ diverse pathogenicity mechanisms including delivery of the RxLR class of cytoplasmic effectors (Jones and Dangl, 2006). The cytoplasm and or its subcellular compartments are exploited for a permissive environment by the RxLR effectors to induce modulations to various essential physiological processes including suppression of plant immunity for pathogen success (Jones & Dangl, 2006, Whisson et al., 2007)
Plants have in turn evolved resistant (R) genes to antagonise effector-mediated modulation of cell function and prevent disease establishment. Currently the most efficient, cost and environmentally friendly management of Phytophthora diseases is the use of resistant germplasm that host cognate R-genes (Dangl et al., 2013, Zhang & Coaker, 2017) . However, R-gene resistance is undermined by their relationship with the RxLR effectors, perceived as an ongoing co-evolutionary arms race Jones & Dangl, 2006, Boller & He, 2009). The RxLR effectors seem to have an upper hand in this race, mirrored by the remarkable records of devastation Phytophthoras disease as they continue to pose a threat to food security and ecological balance in diverse plant communities (Erwin and Ribeiro, 1996, Kamoun et al., 2015).
To advance a sound understanding of RxLR effector biology and their role in Phytophthora pathogenesis, this study employs a bioinformatics analytical pipeline developed around the modular structure of RxLR effectors to identify putative RxLR effector proteins from Phytophthora parasitica. Further, the identified RxLR effectors will be functionally characterised in planta.
Phytophthora parasitica has been highlighted as a model Phytophthora organism for study of Phytophthora-plant interactions (Meng et al., 2014). Further, the pathogen has a broad agroeconomic and ecological significance (Kamoun et al., 2015, Panabieres). making it a suitable model for enquiry of Phytophthora pathogenesis.
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