New Enzymatic Virulence Factors In Phytophthora Infestans

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Plant infection by oomycetes requires penetration of the host cell wall. To accomplish host penetration, pathogens have evolved a range of cell wall degrading enzymes. We recently identified a new family of lytic polysaccharide monooxygenase (LPMO) enzymes in oomycetes. Our studies show that three LPMO encoding genes are highly expressed in Phytophthora infestans during early plant infection. We have characterised a recombinant version of the most abundantly expressed LPMOs and found that it specifically oxidises homogalacturonan (the major pectin in plants). Our preliminary studies show that inactivating the expression of this gene in P. infestans severely impeded the ability of the pathogen to infect plant tissues, indicating a potentially important role in host penetration. Transcriptomic studies reveal a number of other uncharacterised P. infestans genes that are induced in early infection and are potentially targeting the cell wall.

We propose to carry out targeted proteomic studies during the early stages of infection of tomato cells by P. infestans in order to produce a detailed inventory of proteins produced by the pathogen and host during this process. This will provide new insight into the molecular processes and interactions between host and pathogen during wall penetration, and provide us with a list of proteins for further study. We will make a short list of target proteins based on results from loss of gene function experiments, focusing on those that impede infection. We will produce recombinant forms of target proteins in order to characterise biochemical activity and protein structure. We will use molecular localisation studies to characterise the spatio-temporal functioning of the target proteins during infection. We will work with companies, such as Syngenta, in the agrochemical sector to develop strategies for targeting the encoding genes in a crop protection context.

The proposed work fits well with the BBSRC's strategic priorities of sustainably enhancing agricultural production by better countering of diseases or pests (including weeds or parasites) of crops or farmed animals.
The work described in this proposal will benefit the private commercial sector by identifying new virulence factors produced by major crop pathogens, we will provide genes that can serve as targets for precision crop protection strategies using short double stranded nucleic acids for silencing critical pathogen-specific genes. Such approaches are being developed by major players in the agrochemical sector.
New carbohydrate active enzymes, such as the pectin-active LPMOs we recently discovered, may find utility as industrial enzymes. Pectinases are used widely in the food and beverage sector to modify food texture and clarify fruit juices. The York team has a close working relationship with Novozymes (a major producer of industrial enzymes) and will explore this potential with them and other potential industry partners in this sector.
We have assembled an extremely strong group of scientists to maximise the chances of the full promise of the scientific research being realised. In addition, we are committed to seeing that the impacts of the work are maximised. This will, in part, be achieved by working closely with potential industrial partners to ensure that gene targets and enzymes have a route for rapid industrial uptake. In addition, the team has a good record in terms of public outreach and communication.

We will use proven processes to protect IP and publish results in scientific journals and at conferences. We will also use existing UK networks (NIBB, KTNs etc.) to communicate progress through their events and web-based or printed media. When appropriate, discoveries will be disseminated by the University of York and James Hutton Institute to the general media through press releases. To ensure professional management of intellectual property, CNAP and JHI both operate regular IP reviews of all projects. CNAP has an outstanding track record in commercialisation of strategic research through on-going collaborations with companies throughout the biorenewable supply chain.
The programme will provide researchers with wide-ranging skills relevant to the establishment of a vibrant industrial biotechnology and bioenergy research and innovation-led industrial sector in the UK.