Bourlaye Fofana, Ph.D.

Toward evidence that homologs of RPW8 act through salicylic acid signaling in powdery mildew resistance in flax
Vanessa Clemis1,2, Mohsin Zaidi, Frank You3, Chunfang Zheng3, Sylvie Cloutier3, and Bourlaye Fofana1
1Charlottetown Research and Development Centre, Agriculture and Agri-Food Canada, 440 University Avenue, Charlottetown, Prince Edward Island, C1A 4N6, Canada
2University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3, Canada
3Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, Ontario, K1A 0C6, Canada
*bourlaye.fofana@agr.gc.ca
Powdery mildew (PM) is an obligate biotrophic fungus (Podosphaera lini) causing high yield loss to flax (Linum usitatissimum L.). To date, no PM resistance genes have been fully functionally characterized. Using GWAS, we identified a locus harboring three flax homologs of the Arabidopsis RPW8 genes that confer broad-spectrum resistance to powdery mildew. Here, we characterized the gene expression profile of the three RPW8 candidate genes following PM inoculation. The data showed that, similar to RPW8.2 acting through the salicylic acid (SA) signaling pathway, the RPW8 homologs Lus10000835 and Lus10000836 are highly expressed in resistant flax lines compared to the suscpetible lines. In contrast, the flax RPW8 homolog Lus10009328 was highly expressed in the susceptible lines, suggesting a different signaling pathway from the other two homologs. RPW8.1 has been shown to activate ethylene signaling through aminocyclopropane-1-carboxylate oxidase gene isoform 4 (ACO4) and, this elevated ethylene negatively regulates the expression of RPW8.1, thereby attenuating its mediated-cell death and disease resistance when no disease is present to avoid unnecessary defense responses. We conclude that PM resistance induced by RPW8 in flax may mainly be activated through SA signaling pathways, and perhaps similarly to the ethylene signaling in Arabidopsis.

MTA AGR-19473 for incoming plant materials

Mutational Genetics In Diploid Potato In The CRISPR Era
Fofana, B.*1, A. Somalraju1, D. Main1, M. Zaidi1, B. Bizimungu2
1Charlottetown Research and Development Centre, Agriculture and Agri-Food Canada, 440 University Avenue, Charlottetown, Prince Edward Island, C1A 4N6, Canada; 2Fredeicton Research and Development Centre, Agriculture and Agri-Food Canada, 95 Innovation Road, PO Box 20280, Fredericton, NB E3B 4Z7
Cultivated potato (Solanum tuberosum L.) is the fourth most consumed food crop after rice wheat and maize. Cultivated potato is a clonally propagated, autotetraploid crop species with a narrow genetic diversity. Its highly heterozygous, complex genome, and tetrasomic inheritance make its genetic studies and improvement more difficult than grain crops. Recently, diploid potato breeding has regained an interest in the potato genetics community. Genetically, diploid potatoes are easy to work with, can be used as gene donors in the breeding process of cultivated potatoes, and can also be grown on their own as varieties. However, diploid breeding continuum faces many challenges including anti-nutritional factors and self-incompatibilities. Mutations are known as the key drivers for evolution and diversification in plants. In breeding and varietal selection, sources for variation are always sought as starting materials, and in the absence of desired natural variations in breeding populations, targeted or random mutagenesis is applied to induce variations. Recently, a mutagenized pre-breeding diploid potato population was developed at AAFC Charlottetown. Dr. Fofana will give an update on this genetic resource, its characterization, and its potentials in the CRISPR era.

Mutational genetics in the CRISPR era: where do we stand at AAFC?

The Search for Powdery Mildew Resistance Genes in Flax

Till BJ, Aravena Abarzua GA, Howard-Till R, Qian R, Gajardo H, Cloutier S, Fofana B, Soto-Cerda BJ (2020) Genomic improvement of flax using natural variation and induced mutations. Proc 28th Plant and Animal Genome Conference, San Diego, USA, Jan 11-15, W436

Cultivated potato (Solanum tuberosum L.) is the third most consumed food crop after rice and wheat. Potato is an auto tetraploid crop species having a highly heterozygous genetic base and a complex genome making its genetic studies tedious. Recently, diploid potato breeding has regained interest in the potato genetics community. Genetically, diploid potatoes are easy to work with and can be used in the cultivated potato breeding process as genetic resources and also they can be grown on their own as varieties. However, diploid breeding continuum faces many challenges including anti-nutritional factors and self-incompatibilities. Whereas conventional breeding strategies contributed to the releasing of varieties with low SGA, substantial resources are still required to minimizing these anti-nutritional factors. Recently, we developed and characterized an ethyl methane sulfonate mutagenized pre-breeding diploid potato population for identifying lines with low anti-nutritional factors. The data will be presented and discussed in relation to the high potential for diploid potatoes as a complement to tetraploid potatoes and in pre-and post-harvest management contexts.

Somalraju, A., Ghose, K., Main, D., Bizimungu, B., Fofana, B. (2019). Development of pre-breeding diploid potato germplasm displaying wide phenotypic variations as induced by ethyl methane sulfonate mutagenesis. Canadian Journal of Plant Science, [online] 99(2), 138-151. http://dx.doi.org/10.1139/cjps-2018-0189

Pommes de terre : de semence à semence – pouvons-nous changer l’approche?

2018 - Consulter les détails de la publication