ABS59904

HUNTING WHEAT GENES FOR DISEASE RESISTANCE


  • Oral Presentation
  • Plant Pathology
  • 12 Jun 2018 10:20
  • FS-G01, UCD Agriculture and food science Centre
  • View all IPSAM abstracts

Thalia Christodoulou*
UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland

Harriet Benbow
UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland

Ciaran Brennan
UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland

Sobia Ajaz
UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland

Cristobal Uauy
John Innes Centre, Norwich, UK

Paul Nicholson
John Innes Centre, Norwich, UK

Ewen Mullins
Teagasc Crops Research, Carlow, Ireland

Fiona Doohan
UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland

*Presenting Author


Septoria tritici blotch disease is one of the major challenges faced by wheat-breeders and growers. Reverse genetic approaches such as TILLING (Targeting Induced Local Lesions in Genomes) offers great potential for improving crop traits via a non-GM approach. We have screened 500 lines of the wheat cv. Cadenza TILLING population, and identified mutants with altered susceptibility to Zymoseptoria tritici. This phenotypic evaluation highlighted seven lines heterozygous for enhanced resistance and five homozygous for an extremely susceptible phenotype, with wild type cv. Cadenza plants displaying a susceptible response. We are currently backcrossing the resistant lines, in preparation for exome capture of the F5 lines. As 5 generations of crossing in wheat takes several years, we have developed a segregating BC2 population of one of the resistant lines to facilitate mapping of the causative mutation. We will use genotyping by sequencing of the phenotypic extremes of this population to rapidly identify the causative mutations. We anticipate this alternative mapping strategy will allow us to identify candidate mutations within one year.

Fusarium Head blight (FHB) is another devastating disease of wheat. Virus-induced gene silencing (VIGS) is a widely applied reverse genetic method for the determination of gene function under fungal infection of the plant. We have applied VIGS to silence a Fusarium susceptibility gene, discovered in a commercial winter wheat cultivar. Two independent viral constructs were used: one targeted the gene homoeologue on the D genome, while the second one targeted the same gene in all three homeologues. Based on two biological reps, we can see that silencing of this gene gives strong resistance to FHB, confirming that this gene is, in fact, a susceptibility gene for Fusarium infection.