Page 290 - PC2019 Program & Proceedings

PLANT CANADA 2019

P153. Control of Fusarium head blight using the Next-generation of fungicides
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Djavaheri, M. ; T. Bender ; H. Borhan ; S. Clark ; R. Kutcher ; R. Subramaniam ; S. Robinson 1
1 Agriculture and Agri-Food Canada AAFC
National Research Council Canada
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University of Saskatchewan

Fusarium head blight (FHB) is the most devastating disease of cereals which is caused by
Fusarium graminearum (Fg). Infection of the heads of cereals with FHB negatively impacts the yield.
Additionally, accumulation of the mycotoxin Deoxynivalenol (DON) during the progression of the
disease on infected kernels imposes strict limits to its consumption in the food or the feed. Management
of FHB disease in wheat is largely based on basal resistance of cereal plants and chemical control. The
completion of the genomes of wheat and Fg help scientists to develop new tools/more targeted strategies
to control FHB. We examined alterations in the transcriptome of a range of wheat varieties expressing
different levels of kernel resistance to Fg. These results uncovered the Fg genes that are likely to play a
role in early FHB infection of wheat kernels. A subset of early expressed genes involved in FHB infection
were selected for silencing to reduce pathogen growth using Spray-Induced Gene Silencing (SIGS). SIGS
is a non-GMO based technology that uses sequence specificity in dsRNA molecules to transcriptionally
silence target genes. The use of dsRNA molecules to silence genes that support pathogen growth and
mycotoxin production might offer a viable strategy to control future FHB epidemics. Here we report our
progress of identifying novel Fg gene targets that can be used as future next-generation fungicides.

Mohammad Djavaheri (mohammad.djavehri@canada.ca)

P154. Comparative transcriptomics of root responses to pathogenic (Fusarium oxysporum f. sp. lini)
and non-pathogenic (Rhizoglomus irregulare) fungi
I. Quintans; E. Packard; V. Kokkoris; E. Vukicevich; D. Adhikary; Deyholos, M
University of British Columbia, Okanagan

Fusarium oxysporum f. sp. lini is a hemibiotrophic pathogen, and the cause of wilt in flax (Linum
usitatissimum). In contrast, Rhizoglomus irregulare is an arbuscular mycorrhizal fungus that generally
forms mutualisms with flax. Both F. oxysporum and R. irregulare colonize roots at the beginning of their
symbioses. We were therefore interested to compare how gene expression patterns in roots of flax
inoculated with F. oxysporum differed from roots inoculated with R. irregulare. We sowed flax (linseed)
seeds on autoclaved medium (vermiculite with mineral nutrients) that had been inoculated with one of
four treatments: a mock control; F. oxysporum; R. irregulare; or both fungi simultaneously. We
measured plant growth at three time points (9 d, 14 d, 22 d), and found that by 14 d, F. oxysporum-
inoculated plants had significantly lower biomass and shoot length than any of the other treatments. We
extracted RNA from plants at 9 d and 14 d, and used RNA-Seq to compare transcript expression patterns
between the four treatments in three replicates. The number of differentially expressed genes was highest
in the F. oxysporum-inoculated sample with 920 genes increased and 1,061 genes decreased in transcript
abundance (FDR <0.05, FC 2) after 14 d. Only 8 genes had increased transcript abundance, and 69 had
decreased abundance in the R. irregulare sample after 14 d. Here we describe the expression patterns
observed.

Michael Deyholos (michael.deyholos@ubc.ca)

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