Abstract Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe is a major disease of wheat (Triticum aestivum L.). FHB preferentially infects immature spikes and mycotoxins accumulate in developing grains, reducing yield and nutritional quality. The mycotoxins are type B trichothecene group of compounds including deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), and nivalenol (NIV) that also act as virulence factors during FHB infection and disease progression. An enzyme UDP-glucosyl transferase (EC 2.4.1.x) glycosylates DON to deoxynivalenol-3-glucoside (D3G), thus rendering it ineffective as a virulence factor. The present study analysed the association of DON, 3A-DON, and D3G with FHB severity using in vitro spike culture for FHB screening. The mycotoxins in FHB-resistant and -susceptible spikes were extracted using a single step extraction method, and their concentration was determined using an LC-MS/MS method that differentiated all the five mycotoxins. Pairwise comparisons of FHB-resistant and -susceptible spike culture derived variants (SCDV) using Tukey’s method showed significant (P ≤ 0.001) variation for disease severity and accumulation of DON, 3-ADON, and D3G at seven and nine days after fungal inoculation. FHB severity showed a significant positive correlation to the accumulation of DON, 3-ADON, and D3G, but an inverse correlation to the ratio between D3G and DON.

中文翻译：

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利用小麦穗培养评估镰刀菌枯萎病病程和真菌毒素积累

摘要 由禾谷镰刀菌引起的赤霉病（FHB）是小麦（Triticum aestivum L.）的主要病害。FHB 优先感染未成熟的穗状花序，霉菌毒素在发育中的谷物中积累，降低产量和营养质量。霉菌毒素是 B 型单端孢霉烯组化合物，包括脱氧雪腐镰刀菌烯醇 (DON)、3-乙酰脱氧雪腐镰刀菌烯醇 (3-ADON)、15-乙酰脱氧雪腐镰刀菌烯醇 (15-ADON) 和雪腐镰刀菌烯醇 (NIV)，它们在 FHB 感染和疾病进展过程中也充当毒力因子. UDP-葡萄糖基转移酶 (EC 2.4.1.x) 将 DON 糖基化为脱氧雪腐镰刀菌烯醇-3-葡萄糖苷 (D3G)，从而使其作为毒力因子无效。本研究使用体外尖峰培养进行 FHB 筛查，分析了 DON、3A-DON 和 D3G 与 FHB 严重程度的关联。使用单步提取方法提取 FHB 抗性和易感加标中的真菌毒素，并使用区分所有五种真菌毒素的 LC-MS/MS 方法确定它们的浓度。使用 Tukey 方法对 FHB 抗性和易感尖峰培养衍生变体 (SCDV) 进行成对比较显示，在真菌接种后第 7 天和第 9 天，疾病严重程度和 DON、3-ADON 和 D3G 的积累存在显着差异（P ≤ 0.001）。FHB严重程度与DON、3-ADON和D3G的积累呈显着正相关，与D3G和DON之比呈负相关。使用 Tukey 方法对 FHB 抗性和易感尖峰培养衍生变体 (SCDV) 进行成对比较显示，在真菌接种后第 7 天和第 9 天，疾病严重程度和 DON、3-ADON 和 D3G 的积累存在显着差异（P ≤ 0.001）。FHB严重程度与DON、3-ADON和D3G的积累呈显着正相关，与D3G和DON之比呈负相关。使用 Tukey 方法对 FHB 抗性和易感尖峰培养衍生变体 (SCDV) 进行成对比较显示，在真菌接种后第 7 天和第 9 天，疾病严重程度和 DON、3-ADON 和 D3G 的积累存在显着差异（P ≤ 0.001）。FHB严重程度与DON、3-ADON和D3G的积累呈显着正相关，与D3G和DON之比呈负相关。