Haustoria-omics and RNAi gene silencing, to understand gene regulation, fungal virulence and infection during powdery mildew and rust diseases in cereals.

About the Project

Powdery mildews (PMs) and rusts are prevalent plant diseases that compromise the production of many valuable food and horticultural crops, including wheat and barley. As biotrophic pathogenic fungi, PMs and rusts produce specific structures called haustoria, that are essential for infection, are involved in nutrient uptake and the production of virulence factors and effectors to allow these biotrophic pathogens to invade and proliferate on living host cells.

The aim of this project is to investigate further the core proteome and transcriptome of powdery mildew (PM) and rust haustoria, to understand the molecular interplay governing host-pathogen interactions. Ultimately, the discovery of PM virulence genes and their regulatory transcription factors will be instrumental to the design of new crop protection strategies against PMs.

Using proteomics, transcriptomics, and functional genomics, similarly to work published for barley PM (Bindschedler et al, 2009, 2011; Lambertucci et al, 2019, Spanu et al, 2010; Pedersen et al, 2012; Bindschedler et al, 2016), this research will focus in identifying proteins that are commonly associated with haustorial structures across various PM or rust species affecting crops such as wheat, barley, zucchini, strawberry or bean: to identify proteins dominantly expressed in haustoria, when compared to hyphae. Using functional genomics tools and bioinformatics, haustoria associated protein candidates will be further assessed for their role in PM or rust virulence. For this, an RNAi derived transient gene silencing approach has been devised to validate gene candidates, as was shown to silence the barley MLO generequired for susceptibility to barley PM (Lambertucci et al, 2019). Transient protein expression in cucurbit or strawberry plants using agroinfiltration will also allow further characterisation of promising gene candidates. Moreover, a transcriptomics assessment will be performed to identify transcription factors (TFs) involved in promoting virulence, by controlling gene expression in haustoria, including the expression of effector genes. Differential promoter analysis of haustoria expressed genes versus hyphae expressed genes, as well as experimental promoter-TFs binding assays will allow linking of predicted promoter regulatory elements with TFs involved in regulating gene expression of effectors in haustoria.

Research Objectives:

• Omic identification of proteins associated with haustoria from PM and rust using proteomics and transcriptomics.
• Functional genomics for validation of virulence factors using transient gene silencing or Agrobacterium overexpression assays coupled with disease scoring.
• Investigating PM and rust transcription factors (TFs) and promoter regulatory elements controlling expression of effector gene in haustoria usingin silicopromoter analysisand in vitro promoter-TFs binding assays.

We are looking for candidates with a BSc (2:1) or MRes in biological sciences, biochemistry or equivalent, with basic knowledge in molecular biology and interest in plant sciences / molecular plant pathology. Basic knowledge in analytical chemistry, proteomics, mass spectrometry, is desirable but not essential.

The project will be supervised by Dr Laurence Bindschedler.

For informal enquiries and further information on how to apply, please provide your CV and contact Dr Laurence Bindschedler via email Laurence.Bindschedler@rhul.ac.uk.