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

真菌毒素是真菌在有利的环境条件下产生的多种主食的天然污染物。食用受霉菌毒素污染的食品可导致人类和动物患上几种急性和慢性疾病。燕麦变得更受欢迎，因为它们的健康益处可能被一种镰刀菌感染，这种镰刀菌会用真菌毒素T-2/HT2毒素污染燕麦。欧盟规定了这两种毒素的最高推荐摄入量。在燕麦成熟过程中，朗氏杆菌感染燕麦，但不产生明显症状，因此很难评估，除非通过测量成熟燕麦颗粒中的霉菌生物量或通过分析量化存在的T2/HT-2的量。在筛选燕麦品种对叶芝杆菌感染的抗性方面做了有限的工作。气候变化（CC）情景可能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破坏。因此，了解气温升高（+2-4oC）、现有CO2浓度（400 ppm vs 800和1200 ppm CO2）的x2或x3与干旱胁迫的相互作用因素之间的关系是很有意义的。关于这些相互作用的CC因素如何影响这种镰刀菌的感染和燕麦与相关真菌毒素的污染的信息很少。该项目是英国克兰菲尔德大学和爱尔兰都柏林大学之间的一个合作项目，共同解决更好地了解这种重要真菌病原体在不同燕麦品种上的关系，CC因素对感染和霉菌毒素污染的影响以及开发一些阻断真菌毒素生产的新方法等问题。目的可以概括为：(a)在体外检查相互作用的环境因素在燕麦培养基和燕麦籽粒定植期间对F.langsethiae生物合成基因簇的生长和表达的影响，以及对来自英国和爱尔兰的菌株T-2/HT-2毒素产生的影响。相互作用的CC因子对病原体生命周期的影响将被量化。RNA-Seq技术将用于基因调控的研究，首次对毛霉烯A型基因簇进行重点研究；(b)将使用测序方法筛选一系列英国和爱尔兰传统燕麦系，以筛选与不同霉菌毒素污染和潜在抗性相关的不同基因表达谱；(c)“植物内”研究使用两个传统和英国燕麦cv，将检查CC因素对植物/真菌基因表达模式的影响，以及使用未驯化和驯化的F.langsethiae菌株的不同霉菌毒素污染。将量化对T-2/HT-2毒素产生的移位/波动的影响；(d)在正常的农艺和CC条件下，在体外和植物研究中，在分子、菌落和生态系统水平上的优势性方面，将检验朗氏镰刀菌和其他镰刀菌物种，如谷草镰刀菌和孢子毛状镰刀菌以及燕麦真菌群的相对竞争力；(e)使用干扰RNA技术和新型递送系统来干扰T-2/HT-2生产中涉及的关键TRI基因的最小化策略。在植物试验中，将首次测试在正常农艺条件和CC条件下控制毒素产生的效果。

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.