Edwards S G, Pirgozliev S R, Hare M C, Jenkinson P
Crop and Environment Research Centre, Harper Adams University College, Newport, Shropshire TF10 8NB, United Kingdom.
Appl Environ Microbiol. 2001 Apr;67(4):1575-80. doi: 10.1128/AEM.67.4.1575-1580.2001.
We developed a PCR-based assay to quantify trichothecene-producing Fusarium based on primers derived from the trichodiene synthase gene (Tri5). The primers were tested against a range of fusarium head blight (FHB) (also known as scab) pathogens and found to amplify specifically a 260-bp product from 25 isolates belonging to six trichothecene-producing Fusarium species. Amounts of the trichothecene-producing Fusarium and the trichothecene mycotoxin deoxynivalenol (DON) in harvested grain from a field trial designed to test the efficacies of the fungicides metconazole, azoxystrobin, and tebuconazole to control FHB were quantified. No correlation was found between FHB severity and DON in harvested grain, but a good correlation existed between the amount of trichothecene-producing Fusarium and DON present within grain. Azoxystrobin did not affect levels of trichothecene-producing Fusarium compared with those of untreated controls. Metconazole and tebuconazole significantly reduced the amount of trichothecene-producing Fusarium in harvested grain. We hypothesize that the fungicides affected the relationship between FHB severity and the amount of DON in harvested grain by altering the proportion of trichothecene-producing Fusarium within the FHB disease complex and not by altering the rate of DON production. The Tri5 quantitative PCR assay will aid research directed towards reducing amounts of trichothecene mycotoxins in food and animal feed.
我们基于源自单端孢霉烯合酶基因（Tri5）的引物，开发了一种基于聚合酶链式反应（PCR）的检测方法，用于定量检测产单端孢霉烯的镰刀菌。针对一系列小麦赤霉病（FHB，又称赤霉）病原体对这些引物进行了测试，结果发现它们能特异性扩增出25个分离株的260碱基对产物，这些分离株属于6个产单端孢霉烯的镰刀菌物种。对一项田间试验收获的谷物中产单端孢霉烯的镰刀菌数量以及单端孢霉烯霉菌毒素脱氧雪腐镰刀菌烯醇（DON）进行了定量，该田间试验旨在测试杀菌剂甲环唑、嘧菌酯和戊唑醇防治小麦赤霉病的效果。在收获的谷物中，未发现小麦赤霉病严重程度与DON之间存在相关性，但谷物中产单端孢霉烯的镰刀菌数量与DON之间存在良好的相关性。与未处理的对照相比，嘧菌酯对产单端孢霉烯的镰刀菌水平没有影响。甲环唑和戊唑醇显著降低了收获谷物中产单端孢霉烯的镰刀菌数量。我们推测，这些杀菌剂通过改变小麦赤霉病病害复合体中产单端孢霉烯的镰刀菌比例，而非改变DON的产生速率，影响了收获谷物中小麦赤霉病严重程度与DON含量之间的关系。Tri5定量PCR检测方法将有助于开展旨在减少食品和动物饲料中单端孢霉烯霉菌毒素含量的研究。
