Aegilops tauschii is the diploid progenitor of the wheat D subgenome and a valuable resource for wheat breeding, yet, genetic analysis of resistance against Fusarium head blight (FHB) and the major Fusarium mycotoxin deoxynivalenol (DON) is lacking. We treated a panel of 147 Ae. tauschii accessions with either Fusarium graminearum spores or DON solution and recorded the associated disease spread or toxin-induced bleaching. A k-mer-based association mapping pipeline dissected the genetic basis of resistance and identified candidate genes. After DON infiltration nine accessions revealed severe bleaching symptoms concomitant with lower conversion rates of DON into the non-toxic DON-3-O-glucoside. We identified the gene AET5Gv20385300 on chromosome 5D encoding a uridine diphosphate (UDP)-glucosyltransferase (UGT) as the causal variant and the mutant allele resulting in a truncated protein was only found in the nine susceptible accessions. This UGT is also polymorphic in hexaploid wheat and when expressed in Saccharomyces cerevisiae only the full-length gene conferred resistance against DON. Analysing the D subgenome helped to elucidate the genetic control of FHB resistance and identified a UGT involved in DON detoxification in Ae. tauschii and hexaploid wheat. This resistance mechanism is highly conserved since the UGT is orthologous to the barley UGT HvUGT13248 indicating descent from a common ancestor of wheat and barley.

中文翻译：

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一种赋予节节麦和小麦脱氧雪腐镰刀菌烯醇抗性的 UDP-葡萄糖基转移酶的鉴定

Aegilops tauschii是小麦 D 亚基因组的二倍体祖先，是小麦育种的宝贵资源，但缺乏对赤霉病 (FHB) 和主要镰刀菌毒素脱氧雪腐镰刀菌烯醇 (DON) 抗性的遗传分析。我们处理了一组 147 Ae。用禾谷镰刀菌孢子或 DON 溶液对tauschii种质进行了检测，并记录了相关的疾病传播或毒素引起的漂白。基于k -mer的关联作图管道剖析了抗性的遗传基础并确定了候选基因。在 DON 渗透后，9 个种质显示出严重的漂白症状，同时 DON 转化为无毒 DON-3-O-葡萄糖苷的转化率较低。我们确定了基因编码尿苷二磷酸 (UDP)-葡萄糖基转移酶 (UGT) 的染色体 5D 上的AET5Gv20385300作为因果变异和导致截短蛋白质的突变等位基因仅在九个易感种质中发现。这种 UGT 在六倍体小麦中也是多态性的，当在酿酒酵母中表达时，只有全长基因赋予对 DON 的抗性。分析 D 亚基因组有助于阐明 FHB 抗性的遗传控制，并确定了Ae中参与 DON 解毒的 UGT 。tauschii和六倍体小麦。这种抗性机制是高度保守的，因为 UGT 与大麦 UGT HvUGT13248同源，表明来自小麦和大麦的共同祖先。