Food Hygiene and Safety, Meat and Meat Products Research Institute, Faculty of Veterinary Science, University of Extremadura, Avda. de las Ciencias, s/n., 10003 Cáceres, Spain; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Laboratorio de Microbiología de Alimentos, Buenos Aires, Argentina.
Food Hygiene and Safety, Meat and Meat Products Research Institute, Faculty of Veterinary Science, University of Extremadura, Avda. de las Ciencias, s/n., 10003 Cáceres, Spain.
Int J Food Microbiol. 2019 Mar 2;292:48-55. doi: 10.1016/j.ijfoodmicro.2018.12.005. Epub 2018 Dec 7.
Alternaria spp. are major contaminants of wheat crops, causing both economic losses for producers and health risk for consumers due to the accumulation of toxic metabolites. The application of synthetic fungicides in the field may trigger mycotoxin accumulation, since fungistatic levels of those compounds might cause fungal responses to stress. Hence, new alternatives are needed for its control. The aim of this work was to compare the effects of a natural antifungal compound, the antifungal protein PgAFP, and a synthetic commercial one, on Alternaria tenuissima sp.-grp. growth, mycotoxin biosynthesis (tenuazonic acid and alternariols) and the expression of a stress-related gene associated with cell wall integrity (CWI) pathway, in a wheat-based medium at two water activities (a; 0.95 and 0.98 a) conditions associated with the ripening of this grain. The application of both antifungals produced comparable fungistatic effects on Alternaria spp. growth. However, the presence of PgAFP produced a significant reduction in mycotoxins accumulation, whereas this effect was not observed with the commercial antifungal. To our knowledge, this is the first study on the influence of fungicides on the expression of a key gene involved in CWI stress-related pathway in relation to Alternaria mycotoxins accumulation. This information is useful when developing new antifungal methods for foods. The application of PgAFP would be a promising natural strategy for its application in wheat for the control of Alternaria spp.
链格孢属是小麦作物的主要污染物，由于有毒代谢物的积累，会给生产者造成经济损失，并给消费者带来健康风险。田间施用合成杀菌剂可能会引发真菌毒素的积累，因为这些化合物的抑菌水平可能会导致真菌对压力的反应。因此，需要新的替代品来控制它。本工作的目的是比较一种天然抗真菌化合物（抗菌蛋白 PgAFP）和一种合成商业化合物对链格孢属生长、真菌毒素生物合成（ tenuazonic 酸和 alternariols）以及与细胞壁完整性（CWI）途径相关的应激相关基因表达的影响，在基于小麦的培养基中，在与该谷物成熟相关的两个水活度（a；0.95 和 0.98 a）条件下。两种杀菌剂的应用对链格孢属的生长都产生了类似的抑菌作用。然而，PgAFP 的存在显著降低了真菌毒素的积累，而商业杀菌剂则没有观察到这种效果。据我们所知，这是首次研究杀菌剂对与 alternaria 真菌毒素积累相关的 CWI 应激相关途径关键基因表达的影响。当开发用于食品的新的抗真菌方法时，这些信息是有用的。应用 PgAFP 将是一种有前途的天然策略，可用于控制小麦中的链格孢属。
