Quantitative trait loci-dependent analysis of a gene co-expression network associated with Fusarium head blight resistance in bread wheat (Triticum aestivumL.)

Abstract

BackgroundFusarium head blight (FHB) caused by Fusarium graminearum Schwabe is one of the most prevalent diseases of wheat (Triticum aestivum L.) and other small grain cereals. Resistance against the fungus is quantitative and more than 100 quantitative trait loci (QTL) have been described. Two well-validated and highly reproducible QTL, Fhb1 and Qfhs.ifa-5A have been widely investigated, but to date the underlying genes have not been identified.ResultsWe have investigated a gene co-expression network activated in response to F. graminearum using RNA-seq data from near-isogenic lines, harboring either the resistant or the susceptible allele for Fhb1 and Qfhs.ifa-5A. The network identified pathogen-responsive modules, which were enriched for differentially expressed genes between genotypes or different time points after inoculation with the pathogen. Central gene analysis identified transcripts associated with either QTL within the network. Moreover, we present a detailed gene expression analysis of four gene families (glucanases, NBS-LRR, WRKY transcription factors and UDP-glycosyltransferases), which take prominent roles in the pathogen response.ConclusionsA combination of a network-driven approach and differential gene expression analysis identified genes and pathways associated with Fhb1 and Qfhs.ifa-5A. We find G-protein coupled receptor kinases and biosynthesis genes for jasmonate and ethylene earlier induced for Fhb1. Similarly, we find genes involved in the biosynthesis and metabolism of riboflavin more abundant for Qfhs.ifa-5A.

A Brachypodium UDP-Glycosyltransferase Confers Root Tolerance to Deoxynivalenol and Resistance to Fusarium Infection

“…Some secondary metabolism pathways were frequently found to be associated with resistance, such as the induction of the phenylpropanoid pathway and metabolites such as Phe, p-coumarate, and sinapate (Bollina et al, 2011;Kumaraswamy et al, 2011aKumaraswamy et al, , 2011b as well as the production of conjugates of flavonoids/isoflavonoids like naringenin and kaempferol (Kumaraswamy et al, 2011a(Kumaraswamy et al, , 2011b. The induction of jasmonate-regulated allene oxide synthase and 12-oxo-phytodienoic acid reductase (Gottwald et al, 2012;Kugler et al, 2013;Xiao et al, 2013), and the related metabolites linoleic and linolenic acids, jasmonates, and traumatic acid (Bollina et al, 2011;Kumaraswamy et al, 2011a), have been described as markers of quantitative resistance to FHB. Other common features were associated with defense responses such as the induction of b-1,3-glucanases, chitinases, and thaumatin-like proteins, the scavenging of reactive oxygen species, and xenobiotic detoxification by family 1 UDP-glycosyltransferases, glutathione S-transferases, cytochrome P450-monooxygenases, and transporter detoxification (Boddu et al, 2006;Golkari et al, 2007;Jia et al, 2009;Gardiner et al, 2010;Foroud et al, 2012;Kugler et al, 2013;Xiao et al, 2013).…”

“…The induction of jasmonate-regulated allene oxide synthase and 12-oxo-phytodienoic acid reductase (Gottwald et al, 2012;Kugler et al, 2013;Xiao et al, 2013), and the related metabolites linoleic and linolenic acids, jasmonates, and traumatic acid (Bollina et al, 2011;Kumaraswamy et al, 2011a), have been described as markers of quantitative resistance to FHB. Other common features were associated with defense responses such as the induction of b-1,3-glucanases, chitinases, and thaumatin-like proteins, the scavenging of reactive oxygen species, and xenobiotic detoxification by family 1 UDP-glycosyltransferases, glutathione S-transferases, cytochrome P450-monooxygenases, and transporter detoxification (Boddu et al, 2006;Golkari et al, 2007;Jia et al, 2009;Gardiner et al, 2010;Foroud et al, 2012;Kugler et al, 2013;Xiao et al, 2013). Other phenomena that have been linked to resistance to FHB include increased photosynthesis and carbohydrate metabolism involving chloroplast oxygen-evolving enhancer proteins, NAD(P) + -binding proteins, and the pentose phosphate pathway (Kugler et al, 2013;Zhang et al, 2013).…”

“…Other common features were associated with defense responses such as the induction of b-1,3-glucanases, chitinases, and thaumatin-like proteins, the scavenging of reactive oxygen species, and xenobiotic detoxification by family 1 UDP-glycosyltransferases, glutathione S-transferases, cytochrome P450-monooxygenases, and transporter detoxification (Boddu et al, 2006;Golkari et al, 2007;Jia et al, 2009;Gardiner et al, 2010;Foroud et al, 2012;Kugler et al, 2013;Xiao et al, 2013). Other phenomena that have been linked to resistance to FHB include increased photosynthesis and carbohydrate metabolism involving chloroplast oxygen-evolving enhancer proteins, NAD(P) + -binding proteins, and the pentose phosphate pathway (Kugler et al, 2013;Zhang et al, 2013). The biosynthesis and metabolism of riboflavin also have been associated with FHB resistance (Kugler et al, 2013).…”

“…Other phenomena that have been linked to resistance to FHB include increased photosynthesis and carbohydrate metabolism involving chloroplast oxygen-evolving enhancer proteins, NAD(P) + -binding proteins, and the pentose phosphate pathway (Kugler et al, 2013;Zhang et al, 2013). The biosynthesis and metabolism of riboflavin also have been associated with FHB resistance (Kugler et al, 2013).…”

Harnessing Next Generation Sequencing in Climate Change: RNA-Seq Analysis of Heat Stress-Responsive Genes in Wheat (Triticum aestivum L.)

“…It has been successfully used for the relative expression study, editing 5' and 3' ends of annotated genes and functional gene identification with their respective exons and introns (Nagalakshmi et al, 2010). In wheat, RNA-Seq has been mostly used for the identification of novel and conserved stress-responsive genes, especially associated with biotic stress tolerance and nutrientresponsive regulation (Kugler et al, 2013;Oono et al, 2013).…”