Kugler Karl G, Siegwart Gerald, Nussbaumer Thomas, Ametz Christian, Spannagl Manuel, Steiner Barbara, Lemmens Marc, Mayer Klaus F X, Buerstmayr Hermann, Schweiger Wolfgang
Institute for Biotechnology in Plant Production, IFA-Tulln, University of Natural Resources and Life Sciences, A-3430 Tulln, Austria.
BMC Genomics. 2013 Oct 24;14:728. doi: 10.1186/1471-2164-14-728.
Fusarium 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.
We 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.
A 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.
由禾谷镰刀菌（Fusarium graminearum Schwabe）引起的小麦赤霉病是小麦（Triticum aestivum L.）和其他小粒谷物中最普遍的病害之一。对该真菌的抗性是数量性状，已描述了100多个数量性状位点（QTL）。两个经过充分验证且高度可重复的QTL，Fhb1和Qfhs.ifa - 5A已得到广泛研究，但迄今为止其潜在基因尚未确定。
我们利用来自近等基因系的RNA测序数据研究了响应禾谷镰刀菌激活的基因共表达网络，这些近等基因系分别携带Fhb1和Qfhs.ifa - 5A的抗性或感病等位基因。该网络确定了病原体响应模块，这些模块富含接种病原体后不同基因型或不同时间点之间差异表达的基因。中心基因分析确定了与网络内QTL相关的转录本。此外，我们对四个基因家族（葡聚糖酶、NBS - LRR、WRKY转录因子和UDP - 糖基转移酶）进行了详细的基因表达分析，这些基因家族在病原体响应中发挥着重要作用。
网络驱动方法与差异基因表达分析相结合，确定了与Fhb1和Qfhs.ifa - 5A相关的基因和途径。我们发现Fhb1更早诱导了G蛋白偶联受体激酶以及茉莉酸和乙烯的生物合成基因。同样，我们发现Qfhs.ifa - 5A中参与核黄素生物合成和代谢的基因更为丰富。
