Eliminating Fusarium Head Blight susceptibility in wheat

Lead Research Organisation: University of East Anglia
Department Name: Graduate Office

Abstract

Wheat, grown on more land than any other crop, is the most important food grain source for mankind, it provides 20% of our calories, is the major source of protein for the poor, and is by far, the major European crop. Fusarium head blight (FHB) is a major threat to wheat production. FHB reduces yields and leads to the accumulation of mycotoxins in grain. Most UK wheat varieties are highly susceptible to FHB and achieving resistance remains a major challenge internationally. Traditionally, research has focussed on identifying FHB resistance and introgressing genes of major effect into commercial varieties. In this project we aim to exploit our discovery that wheat is complicit in its own downfall. This is because carries FHB susceptibility factors that actually assist the fungus. This finding means that a new approach can be taken - the targeted elimination of susceptibility.
We have identified three locations in the wheat genome that confer susceptibility to FHB. The aim of this project will be to physically map these regions with the long term intention of isolating the genes responsible. A pre-existing gamma-irradiated population of a FHB susceptible wheat cultivar will be used to generate a deletion map of the target regions. Previous studies have established the deletion frequency within these materials. A tiling path of overlapping chromosomal deletions covering the FHB susceptibility loci will be constructed and used to dissect each of them by putting together genomic and FHB resistance data. In this way the position of the FHB susceptibility factor will be refined. The gene content of the newly defined loci will be revealed by alignment of deletions to closely related cereal species for which genome sequence is available (gene content prediction by synteny) and increasingly by the more direct comparison with the rapidly emerging wheat genome sequence. These approaches will allow the identification of candidate FHB susceptibility genes, which will then be studied in detail for expression profiles. If time permits wheat TILLING populations will be screened to identify and disease screen mutants in the susceptibility factor candidates.
In addition to providing an outstanding opportunity to work at the forefront of crop science, this project includes collaboration with a dynamic wheat research team with the company RAGT to provide the student with an insight into commercial plant breeding.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M016919/1 01/10/2015 30/09/2019
1654752 Studentship BB/M016919/1 01/10/2015 30/09/2019 Benjamin Hales
 
Description We have confirmed the presence of a fungal susceptibility factor to Fusarium head blight (FHB) on wheat chromosome arm 4DS and refined the position of this to a small region on the chromosome arm. In doing so, we have also identified a resistance factor to the bleaching caused by the mycotoxin deoxynivalenol (DON) produced by the fungus. This is also on 4DS and we have restricted its position to a small region. Additionally, we have found evidence for an FHB resistance factor to initial infection by the fungus on the long arm of 4D. All three of these factors, influencing FHB susceptibility, are of potential interest to wheat breeders if mapped to a sufficiently small region.

We have further developed a gamma-irradiated Paragon population, making it a potentially valuable resource to the wheat research community. We have made substantial progress in the characterisation of deletions present in the population by skim sequencing ~650 deletion lines. Preliminary analysis appears to confirm this method can reliably detect deletions across the genome. These data will provide genome-wide information on the deletions present in these lines and will be made available to the wheat research community.

Using the irradiated Paragon population, we have performed several rounds of marker screening to identify lines containing small deletions in the FHB susceptibility factor and DON resistance factor intervals. Performing disease/ DON trials on these lines has been sufficient to narrow the susceptibility interval. Final phenotyping experiments are in progress to test the lines identified in the most recent marker screen. This should restrict both FHB susceptibility and DON resistance intervals to just a couple of genes which can be verified using the Cadenza TILLING population.
Exploitation Route The three factors identified may be valuable to wheat breeders if cloned. A deletion line containing a small deletion containing the susceptibility factor, alongside markers to track the deletion, will enable wheat breeders to eliminate the susceptibility factor and improve FHB resistance. The project has also developed a potentially valuable resource for the wheat research community, by developing and characterising a gamma-irradiated Paragon population.
Sectors Agriculture, Food and Drink

 
Description BSPP Travel Fund
Amount £305 (GBP)
Organisation The British Society of Plant Pathology 
Sector Charity/Non Profit
Country Unknown
Start 03/2017 
End 03/2017
 
Description Collaboration regarding a candidate for a DON resistance factor 
Organisation Agriculture and Agri-Food Canada
Country Canada 
Sector Public 
PI Contribution We have been trying to identify the gene(s) underlying a DON resistance factor. We were interested in two aldo-keto reductase genes which have been shown to be capable of detoxifying DON in bacteria. We performed DON application tests on Cadenza TILLING lines (containing mutated copies of the candidate genes), in an attempt to verify the gene of interest. The experiment showed low head damage as a result of DON application but this may be due to the high background mutation rate. We have since identified another interesting target and are using both irradiated Paragon lines and Cadenza TILLING lines to verify the candidate.
Collaborator Contribution Our collaborators agreed to transform E. coli with two candidate genes for a DON resistance factor identified in wheat. The proteins would have been purified and used in DON interaction experiments. However, the transformations were unsuccessful and no further attempts were made in doing so.
Impact N/A
Start Year 2018
 
Description Exploiting a gamma-irradiated Paragon population for mutual benefit 
Organisation University College Dublin
Department School of Biology and Environmental Science
Country Ireland 
Sector Academic/University 
PI Contribution As part of my research, we screened 1000 lines of a gamma-irradiated Paragon population for lines possessing deletions within a specific region of interest on wheat chromosome 4D, and homoeologous regions on 4A and 4B. Coincidentally, our regions of interest on these chromosomes also contains a Fusarium responsive orphan gene (TaFROG) of interest to our collaborators at University College Dublin (UCD). The lines we identified as possessing deletions at the position of the TaFROG genes, corresponding to the 4A, 4B and 4D genomes, we are bulking in the hopes of obtaining homozygous seed. I have designed an additional marker to track TaFROG and, if necessary, will screen additional lines in the population.
Collaborator Contribution Our collaborators at UCD have supplied us with primers to verify the deletions in lines of interest to them. They have also shared data on Fusarium responsive genes in another region of interest to us. This has substantially narrowed down the list of candidate genes likely to be responsible for the phenotype we have observed.
Impact None to date
Start Year 2018
 
Description Interactions with industry: RAGT 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact I have interacted regularly with contacts at the plant breeding company, RAGT. These discussions have assisted in directing the project and has highlighted the potential positive value of the research to industry.
Year(s) Of Engagement Activity 2015,2016,2017,2018
 
Description Meeting report of 13th International Wheat Genetics symposium in British Society of Plant Pathology (BSPP) newsletter autumn/winter 2017 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact I received a travel grant from BSPP to attend the 13th International Wheat Genetics Symposium and was asked to write a meeting report about the conference. This meeting report was published in the autumn/winter 2017 edition of the BSPP newsletter.
Year(s) Of Engagement Activity 2017
 
Description Poster presentation at 14th European Fusarium Seminar (BOKU, Tulln, Austrial) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact I presented a poster at the 14th European Fusarium Seminar in Tulln, Austria. I discussed my research with delegates from across Europe and beyond, based both in academia and industry. This initiated a collaboration with a group in Canada regarding a DON resistance factor I had identified from my research.
Year(s) Of Engagement Activity 2018
 
Description Poster presentation at MonoGram 2015 (NIAB, Cambridge) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact I presented a poster at the MonoGram conference at NIAB, Cambridge. I discussed my research with academics and industry.
Year(s) Of Engagement Activity 2016
 
Description Poster presentation at MonoGram conference 2017 (University of Bristol, Bristol) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact I presented a poster at the MonoGram conference in Bristol. I discussed my research with delegates from both academia and industry.
Year(s) Of Engagement Activity 2017
 
Description Poster presentation at MonoGram conference 2018 (John Innes Centre, Norwich) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact I presented a poster at the MonoGram conference in Norwich. I discussed my research with delegates from both academia and industry.
Year(s) Of Engagement Activity 2018
 
Description Presented poster at John Innes Centre 2016 and 2017 Breeders' Days 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact I presented a poster outlining my research in order to provoke discussion with industry and farmers attending the Breeders' day. I spoke to a number of attendees, who engaged with my research.
Year(s) Of Engagement Activity 2016,2017
 
Description RAGT wheat breeders presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact During my industrial placement, I was invited to present my research to RAGT's wheat breeders, based across Europe, in the form of a conference call presentation. This engaged the wheat breeders at RAGT and promoted discussion of how they could incorporate my findings into their breeding program. I provided RAGT with several lines, of which one should contain a small deletion missing the susceptibility factor I have been tracking.
Year(s) Of Engagement Activity 2018
 
Description Scientist question time with secondary school pupils for Teacher Scientist Network 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact I sat on a panel of staff and students carrying out research at the John Innes Centre. We spoke to five groups of secondary school pupils, who were welcomed to ask us questions about our research, working in science, and beyond.
Year(s) Of Engagement Activity 2018