Deletion of the Aspergillus flavus Orthologue of A. nidulans fluG Reduces Conidiation and Promotes Production of Sclerotia but Does Not Abolish Aflatoxin Biosynthesis
Deletion of the Aspergillus flavus Orthologue of A. nidulans fluG Reduces Conidiation and Promotes Production of Sclerotia but Does Not Abolish Aflatoxin Biosynthesis
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DOI：
10.1128/aem.01241-12
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发表时间：
2012-11-01
影响因子：
4.4
通讯作者：
Ehrlich, Kenneth C.
中科院分区：
文献类型：
--
作者：
Chang, Perng-Kuang;Scharfenstein, Leslie L.;Ehrlich, Kenneth C.
fluG基因是构巢曲霉产孢和杂色曲霉素产生所需基因家族的成员。我们研究了黄曲霉fluG直向同源物在无性发育和黄曲霉毒素生物合成中的作用。缺失A.当在黑暗中在马铃薯葡萄糖琼脂上生长时，黄曲霉产生分生孢子减少约3倍但菌核形成增加30倍的菌株。同时发生的发育变化表明A. flavus FluG对两个过程的相互信号传导途径发挥相反的作用。分生孢子发育的改变部分归因于控制分生孢子梗形成的基因brlA的延迟表达。与A. fluG基因缺失对黄曲霉毒素生物合成无影响。黄色的以.在nidulans中，FluG最近被发现参与脱氢奥斯汀醇的形成，脱氢奥斯汀醇是分生孢子的可扩散信号的组分。共培养实验没有显示A.黄色的这些结果表明，fluG的功能和与分生孢子形成相关的信号通路在两个相关曲霉中是不同的。
The fluG gene is a member of a family of genes required for conidiation and sterigmatocystin production in Aspergillus nidulans. We examined the role of the Aspergillus flavus fluG orthologue in asexual development and aflatoxin biosynthesis. Deletion of fluG in A. flavus yielded strains with an approximately 3-fold reduction in conidiation but a 30-fold increase in sclerotial formation when grown on potato dextrose agar in the dark. The concurrent developmental changes suggest that A. flavus FluG exerts opposite effects on a mutual signaling pathway for both processes. The altered conidial development was in part attributable to delayed expression of brlA, a gene controlling conidiophore formation. Unlike the loss of sterigmatocystin production by A. nidulans fluG deletion strains, aflatoxin biosynthesis was not affected by the fluG deletion in A. flavus. In A. nidulans, FluG was recently found to be involved in the formation of dehydroaustinol, a component of a diffusible signal of conidiation. Coculturing experiments did not show a similar diffusible meroterpenoid secondary metabolite produced by A. flavus. These results suggest that the function of fluG and the signaling pathways related to conidiation are different in the two related aspergilli.