Genes Induced by Fusarium Crown Rot in Wheat and Barley Significantly Overlap with those Induced by Drought Stress
Abstract Background: Fusarium crown rot is a chronic disease in cereal production worldwide. The impact of this disease is highly environmentally dependant and significant yield losses occur mainly in drought-affected crops. Results: In the study reported here, we evaluated possible relationships between genes conferring FCR resistance and drought tolerance using two approaches. The first approach studied FCR induced DEGs (differentially expressed genes) targeting two barley and one wheat loci against a panel of selected genes with known functions in drought tolerance. Of the 149 selected genes, 61% were responsive to FCR infection across the three loci. The second approach was an comparison of the global DEGs induced by FCR infection with the global transcriptomic responses under drought in wheat. This analysis found that approximately 48.0% percent of the DEGs detected one week following drought treatment and 74.4% of the DEGs detected three weeks following drought treatment were also differentially expressed between the susceptible and resistant isolines under FCR infection at one or more timepoints. As for the results from the first approach, the vast majority of common DEGs were downregulated under drought and expressed more highly in the resistant isoline than the sensitive isoline under FCR infection. Conclusions: Results from this study suggest that the resistant isoline in wheat was experiencing less drought stress, which could contribute to the stronger defence response than the sensitive isoline. However, most of the genes induced by drought stress in barley were more highly expressed in the susceptible isolines than the resistant isolines under infection, indicating that genes conferring drought tolerance and FCR resistance may interact differently between these two crop species. Nevertheless, the strong relationship between FCR resistance and drought responsiveness provide further evidence indicating the possibility to enhance FCR resistance by manipulating genes conferring drought tolerance.