International Symposium on Cereal Leaf Blights 2019 | University College Dublin, Ireland | 22-24 May 2019

Identification and characterisation of novel wheat genes that confer resistant to Septoria Tritici Blotch disease during latent phase of the infection

Katarzyna I. Sleczka*
University College Dublin

Harriet R. Benbow
University College Dublin

Gerard Hehir

Ciaran J. Brennan
University College Dublin

Sobia Ajaz
University College Dublin

Binbin Zhou
University College Dublin

Thalia Christodoulou
University College Dublin

Simon Berry

Cristobal Uauy
John Innes Centre

Ewen Mullins

Fiona M. Doohan
University College Dublin

Poster Presentation
Host Genetics and Resistance Breeding

Atrium, UCD O'Brien centre for Science
Poster 44

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Septoria tritici blotch (STB) disease affecting wheat is caused by the fungal pathogen Zymoseptoria tritici. Early detection and initiation of defence responses during the latent phase of infection are crucial in allowing the host to prevent successful pathogen infection. RNAseq data from a doubled-haploid population derived from a cross between cvs. Stigg and Longbow representing the 96-hour response to the pathogen was conducted and a suite of early-response genes have been identified for further characterisation. A second bulk segregant analysis (BSA) RNAseq, composed of two bulks representing the 10-day response to the pathogen was conducted. The first bulk was comprised of six elite resistant cultivars and the second bulk comprised of six elite susceptible cultivars. Following the analysis of the BSA RNAseq data, a variety of candidate genes were identified to be involved in defence against STB. Induction of genes associated with catalytic activity and metal binding were prevalent in the resistant bulk compared to susceptible bulk. Expression of a set of homoeologous Reticulata-like genes were downregulated in the resistant bulk only suggesting, based on studies in other species, a potential burst of reactive oxygen species (ROS). Thirty-five common genes were identified across the two RNAseq datasets, including an adenosylhomocysteinase, a glutathione S-transferase and a serine-type endopeptidase inhibitor. This study shows that defence responses are conserved among wheat cultivars and highlights the importance of the early host response.