BACKGROUND Fusarium head blight (FHB) is a problem of great concern in small grain cereals, especially wheat. A quantitative trait locus (QTL) for FHB resistance (FHB_SFI) located on the long arm of chromosome 2D in the spring wheat genotype Wuhan 1 is a resistance locus which has potential to improve the FHB resistance of bread wheat since it confers effective resistance to wheat breeding lines. Recently, differentially expressed genes (DEG) have been identified by comparing near isogenic lines (NIL) carrying the susceptible and resistant alleles for the 2DL QTL, using RNA-Seq. In the present study, we aimed to identify candidate genes located within the genetic interval for the 2DL QTL for FHB resistance, as assessed by single floret inoculation (FHB_SFI), and possibly contributing to it. RESULTS Combining previous and additional bioinformatics analyses, 26 DEG that were located on chromosome arm 2DL were selected for further characterization of their expression profile by RT-qPCR. Seven of those DEG showed a consistent differential expression profile between either three pairs of near isogenic lines or other genotypes carrying the R and S alleles for the 2DL QTL for FHB resistance. UN25696, which was identified in previous expression work using microarray was also confirmed to have a differential expression pattern. Those eight candidate genes were further characterized in 85 lines of a double haploid mapping population derived from the cross Wuhan 1/Nyubai, the population where the 2DL QTL was originally identified. The expression QTL for gene Traes_2DL_179570792 overlapped completely with the mapping interval for the 2DL QTL for FHB_SFI while the expression QTL for UN25696 mapped near the QTL, but did not overlap with it. None of the other genes had a significant eQTL on chromosome 2DL. Higher expression of Traes_2DL_179570792 and UN25696 was associated with the resistant allele at that locus. CONCLUSIONS Of the 26 DEG from the 2DL chromosome further characterized in this study, only two had an expression QTL located in or near the interval for the 2DL QTL. Traes_2DL_179570792 is the first expression marker identified as associated with the 2DL QTL.

中文翻译：

---

武汉1号小麦枯萎病抗性的2DL QTL表达基因的鉴定与定位。

背景技术镰刀菌枯萎病（FHB）是小谷物尤其是小麦中非常令人关注的问题。武汉小麦基因型武汉1号位于2D染色体长臂上的FHB抗性定量性状基因位点（QTL）是一个抗性基因座，由于它赋予了小麦有效的抗性，因此具有提高面包小麦FHB抗性的潜力繁殖系。最近，使用RNA-Seq通过比较携带2DL QTL敏感和抗性等位基因的近等基因系（NIL），鉴定了差异表达基因（DEG）。在本研究中，我们旨在鉴定通过单小花接种（FHB_SFI）评估的FDL抗性2DL QTL遗传间隔内的候选基因，并可能对其有所贡献。结果结合先前和其他生物信息学分析，选择了位于2DL染色体臂上的26个DEG，以通过RT-qPCR进一步表征其表达谱。这些DEG中的七个在3对近等基因系对或携带2DL QTL的FHB抗性的R和S等位基因的其他基因型之间显示出一致的差异表达谱。在先前使用微阵列的表达工作中鉴定出的UN25696也被证实具有差异表达模式。这八种候选基因在来自双杂交单倍体作图种群的85个品系中得到了进一步的表征，该种群来自最初鉴定2DL QTL的杂交武汉1 / Nyubai种群。基因Traes_2DL_179570792的表达QTL与FHB_SFI的2DL QTL的映射间隔完全重叠，而UN25696的表达QTL在QTL附近映射，但不重叠。其他所有基因均未在2DL号染色体上具有显着的eQTL。Traes_2DL_179570792和UN25696的高表达与该位点的抗性等位基因有关。结论在本研究中进一步表征的来自2DL染色体的26 DEG中，只有两个在2DL QTL的间隔内或附近具有表达QTL。Traes_2DL_179570792是被标识为与2DL QTL相关的第一个表达标记。Traes_2DL_179570792和UN25696的高表达与该位点的抗性等位基因有关。结论在本研究中进一步表征的来自2DL染色体的26 DEG中，只有两个在2DL QTL的间隔内或附近具有表达QTL。Traes_2DL_179570792是被标识为与2DL QTL相关的第一个表达标记。Traes_2DL_179570792和UN25696的高表达与该位点的抗性等位基因有关。结论在本研究中进一步表征的来自2DL染色体的26 DEG中，只有两个在2DL QTL的间隔内或附近具有表达QTL。Traes_2DL_179570792是被标识为与2DL QTL相关的第一个表达标记。