Donovin Coles

Candidature

PhD Candidate

Thesis title

Controlling Contagion: Identifying and targeting genetic loci in agricultural crops to improve broad-spectrum disease resistance

Research project

Chickpea (Cicer arietinum) is an important staple food source in many countries and a vital source of protein in developing countries whereas canola (Brassica napus) is important both as an edible oil and for biofuel production. Due to an increase in demand, the production of chickpea and canola have almost doubled in the last 20 years. However, a threat to sustaining production are plant pathogens which cause major losses worldwide. Reducing losses due to the diseases caused by pathogens requires a fundamental understanding of how they infect their hosts. Hemibiotrophic pathogens are a group of pathogens that initially colonise plant tissue without causing symptoms and then later switch to a destructive phase associated with mass tissue necrosis. To date, the control mechanisms regulating the balance between the two lifestyles is not well understood. For my PhD research project, I am investigating the mechanisms regulating pathogenesis in two model hemibiotrophs: the oomycete Phytophthora medicaginis (host: chickpea) and the fungal pathogen Leptosphaeria maculans (host: canola). The identification of factors controlling the balance between the biotrophic and necrotrophic life stages may provide novel targets to prevent yield reducing disease caused by these pathogens.

Publications

Coles DW, Bithell SL, Mikhael M, Cuddy WS, Plett JM, (2022) 'Chickpea Roots Undergoing Colonisation by Phytophthora medicaginis Exhibit Opposing Jasmonic Acid and Salicylic Acid Accumulation and Signalling Profiles to Leaf Hemibiotrophic Models', Microorganisms, vol.10, no.2, Article no.343

Hill RA, Wong-Bajracharya J, Anwar S, Coles D, Wang M, Lipzen A, Ng V, Grigoriev IV, Martin F, Anderson IC, Cazzonelli CI, Jeffries T, Plett KL, Plett JM, (2022) 'Abscisic acid supports colonization of Eucalyptus grandis roots by the mutualistic ectomycorrhizal fungus Pisolithus microcarpus', New Phytologist, vol.233, no.2, pp 966-982

du Toit Y, Coles DW, Mewalal R, Christie N, Naidoo S, (2020) 'eCALIBRATOR: A Comparative Tool to Identify Key Genes and Pathways for Eucalyptus Defense Against Biotic Stressors', Frontiers in Microbiology, vol.11, Article 216

Naidoo S, Slippers B, Plett JM, Coles D, Oates CN, (2019) 'The Road to Resistance in Forest Trees', Frontiers in Plant Science, vol.10, Article no.273

Supervisors

Dr Jonathan Plett, Dr Henrik Stotz (University of Hertsfordshire), Dr William Cuddy (DPI)