Mechanistic Analysis of Quantitative Disease Resistance in Brassicas by Associative Transcriptomics

• Applicants: Professor Bruce Fitt, Ph.D.; Professorin Barbara Ann Halkier, Ph.D.; Professor Andrzej Kononowicz, Ph.D.; Dr. Christopher J. Ridout; Professor Dr. Andreas von Tiedemann
• Subject Area: Plant Breeding and Plant Pathology ; Plant Physiology
• Term: from 2015 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 263030032

• Final Report Year: 2019

Final Report Abstract

Oilseed rape (OSR, Brassica napus L.) is a major crop grown worldwide for production of edible and industrial oil, biodiesel and protein containing animal feed. Several diseases may threaten or limit the production and crop protection measures are not always sufficient to safeguard harvests. Our research aims to identify and characterise resistance to the most important diseases of OSR so that varieties can be improved. The focus of our work is on Quantitative Disease Resistance (QDR) as this is expected to provide durable control. Using a collection of genetically diverse cultivars, we screened for resistance to the most important diseases of OSR: Sclerotinia, Light leaf Spot, Phoma stem canker, Verticillium, Grey mould and the model bacterial pathogen, Pseudomonas syringae. We also measured immune and biochemical responses in the plants to determine the potential mechanisms of resistance and the underlying genes contributing to this. The results were used to perform a genomewide association study (GWAS) based on expressed genes known as ‘associative transcriptomics’. The analysis enables the identification of gene loci contributing to disease resistance and provides indications about the underlying mechanisms for this. We are keen to encourage the next generation of scientists and established a programme for schools in several locations throughout Europe as part of our project. The schools received seed from our collection of OSR cultivars and performed measurements of growth and development under different conditions. This is the first comprehensive analysis of QDR to multiple diseases in OSR and the potential mechanisms involved. The work will enable associations between QDR to different pathogens to be investigated and provide new insight into the biochemical responses and immunity mechanisms involved. This will provide the basis for develop breeding markers for durable, broad-spectrum resistance to OSR diseases. This will enable more efficient and reduced use of chemical pesticides which will improve OSR production and benefit the environment.

Publications

• (2016). Analysis and Quantification of Glucosinolates. In Stacey G, Birchler J, Ecker J, Martin CR, Stitt M, Zhou J-M (eds.), Current Protocols in Plant Biology 385–409. John Wiley & Sons, Inc., Hoboken, NJ, USA
  Crocoll C, Halkier BA, Burow M
  
• (2017) Arabidopsis late blight: infection of a nonhost plant by Albugo laibachii enables full colonization by Phytophthora infestans. Cellular Microbiology 19 1
  Belhaj K., Cano L. M., Prince D. C., Kemen A., Yoshida K., Dagdas Y. F., Etherington G. J., Schoonbeek H., van Esse H. P., Jones J. D., Kamoun S., Schornack S.
  
• (2017). BMC Biology 15 20. Albugo-imposed changes to tryptophan-derived antimicrobial metabolite biosynthesis may contribute to suppression of non-host resistance to Phytophthora infestans in Arabidopsis thaliana
  Prince D. C., Rallapalli G., Xu D., Schoonbeek H., ÇEvik V., Asai S., Kemen E., Cruz-Mireles N., Kemen A., Belhaj K., Schornack S., Kamoun S., Holub E. B., Halkier B. A., Jones J. D.
  
• (2017). Potential identification of novel sources of resistance to pathogens in a Brassica diversity panel, Aspects of Applied Biology, 134: 213-220
  Mitrousia G.K., Fell H., Gibbard C., Ridout C.J., Schoonbeek H.-J., Stotz H.U., Fitt B.D.L.
  
• (2017). Reduction of antinutritional glucosinolates in Brassica oilseeds by mutation of genes encoding transporters. Nat Biotech. 35, 377-382
  Nour-Eldin, H. H., Madsen, S. R., Engelen, S., Jørgensen M. E., Olsen, C. E., Andersen, J. S., Seynnaeve, D., Verhoye, T., Fulawka, R., Denolf, P., Halkier, B. A.
  
• (2017). Review of combinations of experimental and computational techniques to identify and understand genes involved in innate immunity and effector-triggered defence. Methods. 1;131:120-127
  Stotz H.U., Almeida R., Davey N., Steuber V., Valente G.T.
  
• (2018). Effectiveness of Rlm7 resistance against Leptosphaeria maculans (phoma stem canker) in UK winter oilseed rape cultivars. Plant Pathology, 67: 1339-1353
  Mitrousia G.K., Huang Y.J., Qi A., Sidique S.N.M., Fitt B.D.L.
  
• (2018). Genomic evidence for genes encoding leucine-rich repeat receptors linked to resistance against the eukaryotic extra- and intracellular Brassica napus pathogens Leptosphaeria maculans and Plasmodiophora brassicae. PLOS One. 13, e0198201
  Stotz H.U., Harvey P, Haddadi P., Mashanova A., Kukol A., Larkan N., Borhan H., Fitt B.D.L.