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.
1. ADDIN EN.REFLIST Boller T, He SY, 2009. Innate immunity in plants: an arms race between pattern recognition receptors in plants and effectors in microbial pathogens. Science 324, 742-4.
2. Dangl JL, Horvath DM, Staskawicz BJ, 2013. Pivoting the plant immune system from dissection to deployment. Science 341, 746-51.
3. Erwin DC, Ribeiro OK, 1996. Phytophthora diseases worldwide. American Phytopathological Society (APS Press).
4. Jones JD, Dangl JL, 2006. The plant immune system. nature 444, 323.
5. Kamoun S, Furzer O, Jones JD, et al., 2015. The Top 10 oomycete pathogens in molecular plant pathology. Molecular plant pathology 16, 413-34.
6. Meng Y, Zhang Q, Ding W, Shan W, 2014. Phytophthora parasitica: a model oomycete plant pathogen. Mycology 5, 43-51.
7. Panabieres F, Ali GS, Allagui MB, et al., 2016. Phytophthora nicotianae diseases worldwide: new knowledge of a long-recognised pathogen. Phytopathologia Mediterranea 55, 20-40.
8. Zhang M, Coaker G, 2017. Harnessing effector-triggered immunity for durable disease resistance. Phytopathology 107, 912-9.
My Journal Articles
|Jane Chepsergon, Celiwe Nxumalo, Brenda Salasini, Aquillah Kanzi, Lucy Moleleki. (2022) Short Linear Motifs (SLiMs) in “Core” RxLR effectors of Phytophthora parasitica var. nicotianae: A case of PpRxLR1 effector. Microbiology Spectrum 10(2)