veA is required for toxin and sclerotial production in Aspergillus parasiticus
veA is required for toxin and sclerotial production in Aspergillus parasiticus
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DOI：
10.1128/aem.70.8.4733-4739.2004
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发表时间：
2004-08-01
影响因子：
4.4
通讯作者：
Keller, NP
中科院分区：
文献类型：
--
作者：
Calvo, AM;Bok, J;Keller, NP
人们很早就注意到次生代谢与真菌的发育有关。在Nidulans中，分生孢子和真菌毒素的产生是通过G蛋白信号通路联系在一起的。此外，在根结线虫中，闭壳体的发育和真菌毒素的产生也是由一种名为Vea的基因控制的。在这里，我们报告了在黄曲霉毒素产生真菌寄生中的VEA同源基因的特征。Cleistothecia不是由寄生曲霉产生的；相反，这种真菌产生称为菌核的球形结构，允许在不利条件下生存。从寄生曲霉中删除VEA导致菌核形成受阻以及黄曲霉毒素中间体的产生受阻。我们的结果表明，寄生姬松茸需要aflR和aflJ的表达，而aflR和aflJ调节黄曲霉毒素基因簇的激活。除了这些发现，我们还观察到，VEA的缺失减少了在培养基上和花生种子上的分生孢子。VEA是分生孢子、产生抗性结构和黄曲霉毒素生物合成所必需的，这使得VEA成为控制黄曲霉毒素生物合成或真菌发育的一个很好的候选基因，从而大大减少了它对健康和经济的破坏性影响。
It was long been noted that secondary metabolism is associated with fungal development. In Aspergillus nidulans, conidiation and mycotoxin production are linked by a G protein signaling pathway. Also in A. nidulans, cleistothecial development and mycotoxin production are controlled by a gene called veA. Here we report the characterization of a veA ortholog in the aflatoxin-producing fungus A. parasiticus. Cleistothecia are not produced by Aspergillus parasiticus; instead, this fungus produces spherical structures called sclerotia that allow for survival under adverse conditions. Deletion of veA from A. parasiticus resulted in the blockage of sclerotial formation as well as a blockage in the production of aflatoxin intermediates. Our results indicate that A. parasiticus veA is required for the expression of aflR and aflJ, which regulate the activation of the aflatoxin gene cluster. In addition to these findings, we observed that deletion of veA reduced conidiation both on the culture medium and on peanut seed. The fact that veA is necessary for conidiation, production of resistant structures, and aflatoxin biosynthesis makes veA a good candidate gene to control aflatoxin biosynthesis or fungal development and in this way to greatly decrease its devastating impact on health and the economy.