Characterization of QTL and eQTL controlling early Fusarium graminearum infection and deoxynivalenol levels in a Wuhan 1 x Nyubai doubled haploid wheat population
Citation
Fauteux, F., Wang, Y., Rocheleau, H., Liu, Z., Pan, Y., Fedak, G., McCartney, C., Ouellet, T. (2019). Characterization of QTL and eQTL controlling early Fusarium graminearum infection and deoxynivalenol levels in a Wuhan 1 x Nyubai doubled haploid wheat population. BMC Plant Biology, [online] 19(1), http://dx.doi.org/10.1186/s12870-019-2149-4
Plain language summary
Fusarium head blight (FHB) is a among the most damaging diseases of wheat in Canada and around the world. In this study, we studied early infection by the pathogen in the progeny of a cross-pollination between two moderately FHB resistant wheats. We measured the amount of pathogen tissue and accumulation of a toxin produced by the pathogen two days after inoculation. We identified three chromosome regions controlling limiting pathogen tissue and toxin accumulation. We also used the same plant tissue to study wheat gene expression in response to the pathogen. Here we identified numerous genes with altered gene expression in these three chromosome regions. This information builds on our knowledge of the infection process and provides insight into how wheat defends against this pathogen.
Abstract
Background: Fusarium head blight (FHB) is a major disease of cereal crops, caused by the fungal pathogen Fusarium graminearum and related species. Breeding wheat for FHB resistance contributes to increase yields and grain quality and to reduce the use of fungicides. The identification of genes and markers for FHB resistance in different wheat genotypes has nevertheless proven challenging. Results: In this study, early infection by F. graminearum was analyzed in a doubled haploid population derived from the cross of the moderately resistant wheat genotypes Wuhan 1 and Nyubai. Three quantitative trait loci (QTL) were identified: 1AL was associated with lower deoxynivalenol content, and 4BS and 5A were associated with reduced F. graminearum infection at 2 days post inoculation. Early resistance alleles were inherited from Wuhan 1 for QTL 1AL and 4BS and inherited from Nyubai for the 5A QTL. Cis and trans expression QTL (eQTL) were identified using RNA-seq data from infected head samples. Hotspots for trans eQTL were identified in the vicinity of the 1AL and 4BS QTL peaks. Among differentially expressed genes with cis eQTL within the QTL support intervals, nine genes had higher expression associated with FHB early resistance, and four genes had higher expression associated with FHB early susceptibility. Conclusions: Our analysis of genotype and gene expression data of wheat infected by F. graminearum identified three QTL associated with FHB early resistance, and linked genes with eQTL and differential expression patterns to those QTL. These findings may have applications in breeding wheat for early resistance to FHB.