Cleveland Thomas E, Dowd Patrick F, Desjardins Anne E, Bhatnagar Deepak, Cotty Peter J
US Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA 70124, USA.
Pest Manag Sci. 2003 Jun-Jul;59(6-7):629-42. doi: 10.1002/ps.724.
Mycotoxins (ie toxins produced by molds) are fungal metabolites that can contaminate foods and feeds and cause toxic effects in higher organisms that consume the contaminated commodities. Therefore, mycotoxin contamination of foods and feeds results is a serious food safety issue and affects the competitiveness of US agriculture in both domestic and export markets. This article highlights research accomplished by Agricultural Research Service (ARS) laboratories on control of pre-harvest toxin contamination by using biocontrol, host-plant resistance enhancement and integrated management systems. Emphasis is placed on the most economically relevant mycotoxins, namely aflatoxins produced by Aspergillus flavus, Link, trichothecenes produced by various Fusarium spp and fumonisins produced by F verticillioides. Significant inroads have been made in establishing various control strategies such as development of atoxigenic biocontrol fungi that can outcompete their closely related, toxigenic cousins in field environments, thus reducing levels of mycotoxins in the crops. Potential biochemical and genetic resistance markers have been identified in crops, particularly in corn, which are being utilized as selectable markers in breeding for resistance to aflatoxin contamination. Prototypes of genetically engineered crops have been developed which: (1) contain genes for resistance to the phytotoxic effects of certain trichothecenes, thereby helping reduce fungal virulence, or (2) contain genes encoding fungal growth inhibitors for reducing fungal infection. Gene clusters housing the genes governing formation of trichothecenes, fumonisins and aflatoxins have been elucidated and are being targeted in strategies to interrupt the biosynthesis of these mycotoxins. Ultimately, a combination of strategies using biocompetitive fungi and enhancement of host-plant resistance may be needed to adequately prevent mycotoxin contamination in the field. To achieve this, plants may be developed that resist fungal infection and/or reduce the toxic effects of the mycotoxins themselves, or interrupt mycotoxin biosynthesis. This research effort could potentially save affected agricultural industries hundreds of millions of dollars during years of serious mycotoxin outbreaks.
霉菌毒素（即由霉菌产生的毒素）是真菌代谢产物，可污染食品和饲料，并对食用受污染商品的高等生物产生毒性作用。因此，食品和饲料中的霉菌毒素污染是一个严重的食品安全问题，影响美国农业在国内和出口市场的竞争力。本文重点介绍了农业研究局（ARS）实验室在利用生物防治、增强宿主植物抗性和综合管理系统控制收获前毒素污染方面所取得的研究成果。重点关注的是与经济关联最大的霉菌毒素，即黄曲霉（Aspergillus flavus, Link）产生的黄曲霉毒素、多种镰刀菌属（Fusarium spp）产生的单端孢霉烯族毒素以及轮枝镰孢菌（F verticillioides）产生的伏马毒素。在建立各种控制策略方面已取得重大进展，例如开发非产毒生物防治真菌，这类真菌在田间环境中能够胜过与其亲缘关系密切的产毒同类真菌，从而降低作物中的霉菌毒素水平。在作物尤其是玉米中已鉴定出潜在的生化和遗传抗性标记，这些标记正被用作抗黄曲霉毒素污染育种中的选择标记。已开发出基因工程作物原型，这些作物：（1）含有抵抗某些单端孢霉烯族毒素植物毒性作用的基因，从而有助于降低真菌毒力；或（2）含有编码真菌生长抑制剂的基因以减少真菌感染。已阐明负责单端孢霉烯族毒素、伏马毒素和黄曲霉毒素形成的基因簇，并将其作为阻断这些霉菌毒素生物合成策略的目标。最终，可能需要结合使用生物竞争真菌和增强宿主植物抗性的策略，以充分预防田间的霉菌毒素污染。为此，可培育出抵抗真菌感染和/或降低霉菌毒素自身毒性作用或阻断霉菌毒素生物合成的植物。在霉菌毒素严重爆发的年份，这项研究工作有可能为受影响的农业产业节省数亿美元。
