Hordeum vulgare cultivar:M69, Lacey and Chevron Transcriptome or Gene expression. Hordeum vulgare cultivar:M69, Lacey and Chevron

Fusarium graminearum infects barley spikes and causes Fusarium head blight (FHB), a major disease problem worldwide. Resistance to FHB is partial and controlled by quantitative trait loci (QTL) of which two are located on barley chromosomes 2H bin8 (2Hb8) and 6H bin7 (6Hb7). To understand the molecular mechanisms of FHB resistance, transcriptomes of near-isogenic lines (NILs) carrying Chevron-derived resistant alleles for the two QTL and recurrent parents (M69 and Lacey) were investigated with RNA sequencing after F. graminearum or mock inoculation. A total of 2,083 FHB-responsive transcripts were detected and provide a gene expression atlas for the barley-F. graminearum interaction. Comparative analysis of the 2Hb8 resistant (R) NIL and M69 revealed that the 2Hb8 R NIL exhibited an elevated defense response in the absence of fungal infection and responded quicker than M69 upon fungal infection. The 6Hb7 R NIL displayed a more rapid induction of a set of defense genes than Lacey during the early stage of fungal infection. Overlap of differentially accumulated genes were identified between the two R NILs, suggesting that certain defense mechanisms may represent basal resistance to F. graminearum and/or general biotic stress response and were co-regulated by the two QTL. Long noncoding RNAs (lncRNAs) have emerged as potential key regulators of transcription. A total of 12,366 lncRNAs were identified of which 604 were FHB responsive. The current transcriptomic analysis revealed the differential mechanisms conferred by two QTL in response to F. graminearum infection and identified genes and lncRNAs that were associated with FHB resistance.

禾谷镰孢菌（Fusarium graminearum）可侵染大麦穗部并引发赤霉病（Fusarium head blight, FHB），该病害是全球范围内的主要农业病害问题。大麦对赤霉病的抗性为部分抗性，由数量性状位点（quantitative trait loci, QTL）调控，其中两个抗性位点分别定位于大麦2H染色体bin8（2Hb8）和6H染色体bin7（6Hb7）区域。为解析赤霉病抗性的分子机制，本研究针对携带上述两个QTL的Chevron来源抗性等位基因的近等基因系（near-isogenic lines, NILs）及其轮回亲本（M69与Lacey），在禾谷镰孢菌接种或模拟接种后开展了RNA测序，以分析其转录组特征。研究共检测到2083个赤霉病响应转录本，构建了大麦-禾谷镰孢菌互作的基因表达图谱。对2Hb8抗性（R）近等基因系与轮回亲本M69的比较转录组分析显示，2Hb8抗性近等基因系在未受真菌侵染时即呈现增强的防御响应，且在真菌侵染后的响应速度快于M69。6Hb7抗性近等基因系则在真菌侵染早期，可更快速地诱导一系列防御基因的表达。在两个抗性近等基因系中均鉴定到了重叠的差异积累基因，这提示部分防御机制可能属于对禾谷镰孢菌的基础抗性和/或通用生物胁迫响应，且受这两个QTL共同调控。长链非编码RNA（long noncoding RNAs, lncRNAs）作为转录调控的关键潜在调控因子，近年来受到广泛关注。本研究共鉴定出12366个长链非编码RNA，其中604个为赤霉病响应型转录本。本转录组分析揭示了两个QTL介导的赤霉病抗性差异响应机制，并鉴定出与赤霉病抗性相关的编码基因及长链非编码RNA。