Oats for the future: deciphering potential of host resistance and RNAi to minimise mycotoxin contamination under present and future climate scenarios

霉菌毒素是真菌在有利的环境条件下产生的各种主食的天然污染物。食用被真菌毒素污染的食物可能会导致人类和动物患上几种急性和慢性疾病。燕麦已经变得更受欢迎，因为如果它们的健康益处可以被镰刀菌物种F.langsethiae感染，它可以用霉菌毒素T-2/HT2毒素污染燕麦。欧盟对这两种毒素的最高推荐水平有所规定。轮纹夜蛾在燕麦成熟期间侵染燕麦，但不会产生明显的症状，因此很难进行评估，除非通过测量成熟燕麦粒中的霉菌生物量或通过分析量化T2/HT-2的含量。在筛选燕麦品种抗黄曲霉病菌方面所做的工作有限。气候变化(CC)的情景可能会加剧真菌感染和真菌毒素的产生，部分原因是害虫繁殖增加和对成熟作物的损害。因此，有兴趣了解CC的相互作用因素之间的关系，包括高温(+2-4oC)、x2或x3现有二氧化碳浓度(400ppm对800和1200ppm二氧化碳)与干旱胁迫事件之间的关系。关于这些相互作用的CC因子如何影响该镰刀菌种的感染和燕麦受相关真菌毒素污染的信息很少。该项目是英国克兰菲尔德大学和爱尔兰都柏林大学学院的合作项目，旨在共同解决以下问题：更好地了解这种重要的真菌病原体与不同燕麦品种之间的关系，CC因子对感染和真菌毒素污染的影响，以及开发一些新的方法来阻止真菌毒素的产生。其目的可以概括为：(A)体外研究相互作用的环境因素对燕麦基质和燕麦谷物定殖过程中真菌生长和生物合成基因簇表达的影响，以及对来自英国和爱尔兰的菌株产生T-2/HT-2毒素的影响。相互作用的CC因素对病原菌生命周期的影响将被量化。将利用RNA-Seq技术研究基因调控，首次以毛霉烯A型基因簇为重点；(B)将使用测序方法筛选一系列英国和传统爱尔兰燕麦品系，以寻找与差异霉菌毒素污染和潜在抗药性相关的差异基因表达谱；(C)利用两个传统燕麦品系和英国燕麦变异株，将研究CC因子对植物/真菌基因表达模式的影响，以及使用未驯化和驯化的F.langsethiae菌株来检测CC因子对植物/真菌基因表达模式的影响。将量化对T-2/HT-2毒素产生的转变/波动的影响；(D)将在体外和植物研究中，在正常的农艺和CC条件下，检查F.langsethiae与其他镰刀菌物种，如禾谷镰刀菌和F.porotrichioides以及燕麦真菌生物群的相对竞争力；以及(E)利用干扰RNA技术和新型传递系统，最大限度地减少干扰T-2/HT-2生产所涉及的关键三基因的策略。在植物试验中，将首次测试在正常农艺条件和CC条件下的毒素产生的防治效果。

Mycotoxins are natural contaminants of a wide range of staple foods produced by fungi under conducive environmental conditions. The consumption of mycotoxin contaminated foods can result in several acute and chronic diseases in humans and animals. Oats, which have become more popular because if their health benefits can be infected by a Fusarium species, F.langsethiae, which can contaminate oats with the mycotoxins T-2/HT2 toxins. The EU has maximum recommended levels for these two toxins in place. F.langsethiae infects oats during ripening but produces no visible symptoms and is thus difficult to assess except by measuring the mould biomass in the ripening oat grain or by analytically quantifying the amounts of T2/HT-2 present. Limited work has been done on screening oat cultivars for resistance to F.langsethiae infection. Climate change (CC) scenarios has been suggested to probably exacerbate fungal infection and mycotoxin production partially via increases in pest reproduction and damage to ripening crops. Thus there is interest in understanding the relationships between interacting factors of CC including elevated temperature (+2-4oC), x2 or x3 existing CO2 concentrations (400 ppm vs 800 and 1200 ppm CO2) and episodes of drought stress. Very little information is available on how these interacting CC factors impact on infection by this Fusarium species and contamination of oats with the associated mycotoxin. This project is a collaborative project between Cranfield University in the UK and University College Dublin in Ireland to jointly address the issues of a better understanding of the relationship between this important fungal pathogen on different oat cultivars, the impact that CC factors will have on infection and mycotoxin contamination and the development of some novel methods for blocking the production of the mycotoxins.The objectives can be summarised as being (a) In vitro examination of the effect of interacting environmental factors on growth and expression of biosynthetic gene clusters of F.langsethiae during colonisation of oat-based media and oat grains and on T-2/HT-2 toxin production by strains from the UK and Ireland. The effect of interacting CC factors the life cycle of the pathogen will be quantified. RNA-Seq technology will be used to study the gene regulation, focusing on the trichothecenes type A gene cluster for the first time; (b) a range of UK and Heritage Irish oat lines will be screened for distinct gene expression profiles relevant to differential mycotoxin contamination and potential resistance using sequencing approaches; (c) 'In planta' studies using two heritage and UK oat CVs will examine CC factors on plant/fungus gene expression patterns and differential mycotoxin contamination using non-acclimatised and acclimatised strains of F.langsethiae. The effects on shifts/fluctuations in T-2/HT-2 toxin production will be quantified; (d) the relative competitiveness of F.langsethiae and other Fusarium species such as F.graminearum and F.sporotrichioides and oat mycobiota will be examined under normal agronomic and CC conditions in in vitro and in planta studies on dominance at a molecular, colony and ecosystem level; and (e) minimisation strategies using interference RNA technology and novel delivery systems to interfere with the key TRI genes involved in T-2/HT-2 production. In planta trials will be carried out to test control efficacy of toxin production under normal agronomic and CC conditions for the first time.