Haustoria-omics with proteomics, transcriptomics, and gene silencing, to understand fungal pathogenicity and plant resistance during powdery mildew disease in food crops

Powdery mildews (PMs) are prevalent plant diseases that compromise the production of many valuable food and horticultural crops, including cereals, strawberry, cucurbits and pea. As biotrophic pathogenic fungi, PMs 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. Moreover, an extrahaustorial membrane is produced by the plant around the haustorium, where plant proteins are recruited for modulating either host susceptibility or immunity.

The aim of this project is to investigate the core proteome and transcriptome of powdery mildew (PM) haustoria, to understand the molecular interplay governing host susceptibility/ immunity and fungal virulence. Ultimately, the discovery of host susceptibility genes, as well as 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 species affecting crops such as wheat, barley, strawberry, zucchini or pea: (i) on the plant side, to identify proteins associated with the plant extrahaustorial membrane and (ii) on the PM fungus side, 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 host susceptibility or resistance, and PM 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 gene required 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 plant and PM proteins associated with haustoria using proteomics and transcriptomics.

Functional genomics for validation of new host susceptibility factors or PM proteins required for virulence using transient gene silencing or Agrobacterium overexpression assays coupled with disease scoring.

Investigating PM transcription factors (TFs) and promoter regulatory elements controlling expression of effector gene in haustoria using in silico promoter analysis and 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.

It will be supervised by Dr Laurence Bindschedler (RHUL), with expertise in fungal pathogens, powdery mildews, gene silencing, proteomics; Dr Stuart Snowden (RHUL) expert in mass spectrometry; Dr Andrew Armitage (NRI, University of Greenwich) expert in bioinformatics, fungal genomics, transcriptomics and pathogenicity. 

To apply follow link and instructions at https://www.royalholloway.ac.uk/studying-here/applying/postgraduate/how-to-apply/ . Please indicate “Bindschedler” in your application. Application deadline 11 June 2023

For informal enquiries please contact Dr Laurence Bindschedler via email [Email Address Removed].