Research Output
1 - 7 of 7
Publication
International Symposium on Cereal Leaf Blights (ISCLB) 2019: Book of Abstracts
2019-04-24, Feechan, Angela, Benbow, Harriet, Tiley, Anna, Gibriel, Hesham, Casey, Edward, Doohan, Fiona M., Feechan, Angela
International Symposium on Cereal Leaf Blights is one of the most important conferences for the Cereal Blight Community including academics, researchers, agency partners and commercial breeders. The Symposium aims to bring together the whole research community - not just in academia but also in research centres and institutes and across government and agency organisations - with an interest in a wide variety of issues around cereal leaf blights. Over the course of three days, we participate in extensive debate and discussion across our seven Symposium topics: Evolution and Population Biology, Cultural management, fungicide resistance and epidemiology, Pathogen Functional Genetics and Genomics, Host-Pathogen Interactions, Host genetics and Resistance Breeding, Secondary Metabolism and Physiology and Special Topics.
Publication
Wheat Encodes Small, Secreted Proteins That Contribute to Resistance to Septoria Tritici Blotch
2020-05-12, Zhou, Binbin, Benbow, Harriet, Brennan, Ciarán J., Arunachalam, Chanemougasoundharam, Karki, Sujit Jung, Mullins, Ewen, Feechan, Angela, Burke, James, Doohan, Fiona M.
During plant–pathogen interactions, pathogens secrete many rapidly evolving, small secreted proteins (SSPs) that can modify plant defense and permit pathogens to colonize plant tissue. The fungal pathogen Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), one of the most important foliar diseases of wheat, globally. Z. tritici is a strictly apoplastic pathogen that can secrete numerous proteins into the apoplast of wheat leaves to promote infection. We sought to determine if, during STB infection, wheat also secretes small proteins into the apoplast to mediate the recognition of pathogen proteins and/or induce defense responses. To explore this, we developed an SSP-discovery pipeline to identify small, secreted proteins from wheat genomic data. Using this pipeline, we identified 6,998 SSPs, representing 2.3% of all proteins encoded by the wheat genome. We then mined a microarray dataset, detailing a resistant and susceptible host response to STB, and identified 141 Z. tritici- responsive SSPs, representing 4.7% of all proteins encoded by Z. tritici – responsive genes. We demonstrate that a subset of these SSPs have a functional signal peptide and can interact with Z. tritici SSPs. Transiently silencing two of these wheat SSPs using virus-induced gene silencing (VIGS) shows an increase in susceptibility to STB, confirming their role in defense against Z. tritici.
Publication
A small secreted protein from Zymoseptoria tritici interacts with a wheat E3 ubiquitin to promote disease
2021-02-02, Karki, Sujit Jung, Reilly, Aisling, Zhou, Binbin, Mascarello, Maurizio, Burke, James, Doohan, Fiona M., Douchkov, Dimitar, Schweizer, Patrick, Feechan, Angela
Septoria Tritici Blotch, caused by the ascomycete fungus Zymoseptoria tritici, is a major threat to wheat production worldwide. The Z. tritici genome encodes many small, secreted proteins (ZtSSP) that likely play a key role in the successful colonisation of host tissues. However, few of these ZtSSPs have been functionally characterised for their role during infection. In this study, we identified and characterised a small, conserved cysteine-rich secreted effector from Zymoseptoria tritici which has homologues in other plant pathogens in the dothideomycetes. ZtSSP2 was expressed throughout Z. tritici infection in wheat with the highest levels observed early during infection. A yeast two-hybrid assay revealed an interaction between ZtSSP2 and wheat E3 ubiquitin ligase in yeast and this was further confirmed in planta using bimolecular fluorescence complementation, and co-immunoprecipitation. Down-regulation of this wheat E3 ligase using virus-induced gene silencing, increased the susceptibility of wheat to Septoria tritici blotch (STB). Together these results suggest that TaE3UBQ likely plays a role in plant immunity to defend against Z. tritici.
Publication
Spot the difference on laurel leaves
2020-07, McGuinness, Brian, Smith, Leighton, Feechan, Angela, Grogan, Helen
Researchers from TEAGASC and UCD are investigating disease issues in cherrylaurel, an important species for the Irish cut foliage sector.
Publication
The potential of Miscanthus to harbour known cereal pathogens
2015-01, Glynn, E., Brennan, J. M., Walsh, EilÃn, Feechan, Angela, McDonnell, Kevin
Miscanthus holds great potential as a bioenergy crop and Ireland has ideal conditions for its cultivation, however limited information is available about the interactions between Miscanthus and soil fungi which are pathogenic to other crops grown in Ireland and the UK. Miscanthus may therefore be susceptible to soil-borne pathogens present in the soil prior to crop establishment or may harbour pathogens and facilitate transmission of disease to other crops. The response of Miscanthus to a number of fungal species was recorded to determine the vulnerability of Miscanthus to some of the most important cereal pathogens in Ireland. The microbial species were selected based on their presence in soil and their known pathogenicity towards cereal crops currently grown in Ireland. A number of fungi caused a significant level of infection on detached Miscanthus leaves: Rhizoctonia solani, Fusarium poae (Fusarium sporotrichiella var. poae) and Sordaria fimicola caused the greatest level of symptoms while Fusarium culmorum caused the greatest visual disease symptoms in living tissue during whole plant tests. The results suggest that Miscanthus is susceptible to a number of cereal fungal pathogens, and that of all the species investigated Fusarium species pose the greatest threat to Miscanthus plantings in Ireland. Fusarium is a known causative agent of blight in cereals, thus its ability to survive both on living and discarded Miscanthus tissue is important as it suggests that Miscanthus could act as a 'disease bridge' for cereal pathogens.
Publication
Taxonomically Restricted Wheat Genes Interact With Small Secreted Fungal Proteins and Enhance Resistance to Septoria Tritici Blotch Disease
2020-05-07, Brennan, Ciarán J., Zhou, Binbin, Benbow, Harriet, Ajaz, Sobia, Karki, Sujit Jung, Feechan, Angela, Doohan, Fiona M., et al.
Understanding the nuances of host/pathogen interactions are paramount if we wish to effectively control cereal diseases. In the case of the wheat/Zymoseptoria tritici interaction that leads to Septoria tritici blotch (STB) disease, a 10,000-year-old conflict has led to considerable armaments being developed on both sides which are not reflected in conventional model systems. Taxonomically restricted genes (TRGs) have evolved in wheat to better allow it to cope with stress caused by fungal pathogens, and Z. tritici has evolved specialized effectors which allow it to manipulate its’ host. A microarray focused on the latent phase response of a resistant wheat cultivar (cv. Stigg) and susceptible wheat cultivar (cv. Gallant) to Z. tritici infection was mined for TRGs within the Poaceae. From this analysis, we identified two TRGs that were significantly upregulated in response to Z. tritici infection, Septoria-responsive TRG6 and 7 (TaSRTRG6 and TaSRTRG7). Virus induced silencing of these genes resulted in an increased susceptibility to STB disease in cvs. Gallant and Stigg, and significantly so in the latter (2.5-fold increase in STB disease). In silico and localization studies categorized TaSRTRG6 as a secreted protein and TaSRTRG7 as an intracellular protein. Yeast two-hybrid analysis and biofluorescent complementation studies demonstrated that both TaSRTRG6 and TaSRTRG7 can interact with small proteins secreted by Z. tritici (potential effector candidates). Thus we conclude that TRGs are an important part of the wheat-Z. tritici co-evolution story and potential candidates for modulating STB resistance.
Publication
Isolate specific responses of the non-host grass Brachypodium distachyon to the fungal pathogen Zymoseptoria tritici, compared to wheat
2021-02, Reilly, Aisling, Karki, Sujit Jung, Twamley, Anthony, Tiley, Anna, Kildea, Steven, Feechan, Angela
Septoria tritici blotch (STB) is an important foliar disease of wheat that is caused by the fungal pathogen Zymoseptoria tritici. The grass Brachypodium distachyon has been used previously as a model system for cereal-pathogen interactions. In this study, we examined the non-host resistance (NHR) response of B. distachyon to two different Z. tritici isolates in comparison to wheat. These isolates vary in aggressiveness on wheat cv. Remus displaying significant differences in disease and pycnidia coverage. Using microscopy, we found that similar isolate specific responses were observed for H2O2 accumulation and cell death in both wheat and B. distachyon. Despite this, induction of isolate specific patterns of defence gene expression by Z. tritici did differ between B. distachyon and wheat. Our results suggest that phenylalanine ammonia lyase (PAL) expression may be important for NHR in B. distachyon while pathogenesis-related (PR) genes and expression of genes regulating reactive oxygen species (ROS) may be important to limit disease in wheat. Future studies of the B. distachyon-Z. tritici interaction may allow identification of conserved plant immunity targets which are responsible for the isolate specific responses observed in both plant species.