Repression of deoxynivalenol accumulation and expression of Tri genes in Fusarium culmorum by fungicides in vitro
Repression of deoxynivalenol accumulation and expression of Tri genes in Fusarium culmorum by fungicides in vitro
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DOI：
10.1111/j.1365-3059.2004.00941.x
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发表时间：
2004-02-01
期刊：
影响因子：
2.7
通讯作者：
Nicholson, P
中科院分区：
文献类型：
--
作者：
Covarelli, L;Turner, AS;Nicholson, P
建立了一种用于监测脱氧雪腐镰刀菌烯醇(DON)积累、真菌生长和毛霉烯生物合成相关基因(称为Tri基因)表达的特定培养基。在液体培养中，DON在Tri6最高表达后不久积累，并与Tri5的表达一致。这通常是在接种后96小时。在此基础上，研究了杀菌剂嘧菌酯、三氟菌酯、甲苯氧菌酯和戊唑醇的亚致死浓度对镰刀菌生物合成三环烯DON的影响。在一定浓度范围内，杀菌剂三氟菌酯和嘧菌酯显著降低了DON在培养基中的积累。尽管DON的含量低于未经修饰的培养物中的水平，但甲苯西林和戊唑醇并不能显著减少DON的积累。在毛霉烯生物合成开始之前，添加到培养物中的三氟菌酯显著减少DON的积累。RT-PCR分析Tri6和Tri5基因的表达表明，三氟菌酯通过抑制毛霉烯的生物合成而发挥作用。
A defined medium was developed in which to monitor deoxynivalenol (DON) accumulation, fungal growth and expression of genes involved in trichothecene biosynthesis (designated Tri genes). In liquid culture, DON accumulated shortly after maximum expression of Tri6 and coincident with expression of Tri5. This was generally 96 h after inoculation. The effects of sublethal concentrations of the fungicides azoxystrobin, trifloxystrobin, kresoxim-methyl and tebuconazole on biosynthesis of the trichothecene DON by Fusarium culmorum were studied using this medium. The strobilurin fungicides trifloxystrobin and azoxystrobin significantly reduced the accumulation of DON in culture medium at a range of concentrations. Kresoxim-methyl, also a strobilurin, and tebuconazole, a triazole, did not significantly reduce the accumulation of DON, although levels were lower than those in nonamended cultures. Trifloxystrobin significantly reduced the accumulation of DON when added to cultures before initiation of trichothecene biosynthesis. RT-PCR assays of the expression of Tri6 and Tri5 genes indicated that trifloxystrobin acted by inhibiting the initiation of trichothecene biosynthesis.