The Aspergillus flavus Homeobox Gene, hbx1, is Required for Development and Aflatoxin Production.
The Aspergillus flavus Homeobox Gene, hbx1, is Required for Development and Aflatoxin Production.
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DOI：
10.3390/toxins9100315
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发表时间：
2017-10-12
期刊：
影响因子：
4.2
通讯作者：
Chanda A
中科院分区：
文献类型：
--
作者：
Cary JW;Harris-Coward P;Scharfenstein L;Mack BM;Chang PK;Wei Q;Lebar M;Carter-Wientjes C;Majumdar R;Mitra C;Banerjee S;Chanda A
同源异型盒蛋白是一类高度保守的转录因子，可调节靶基因的表达，尤其是那些参与发育的基因。在丝状真菌中，同源异型盒基因是正常分生孢子形成和子实体形成所必需的。在本研究中，我们在产黄曲霉毒素的子囊菌黄曲霉中鉴定出8个同源异型盒（hbx）基因，并确定了它们在生长、产孢和菌核产生中的各自作用。8个基因中的7个被破坏对真菌的生长和发育几乎没有影响。然而，在两种形态不同的黄曲霉菌株CA14和AF70中，同源异型盒基因AFLA_069100（被命名为hbx1）被破坏，导致分生孢子和菌核以及黄曲霉毒素B1和B2、环匹阿尼酸和黄曲霉震颤素完全无法产生。显微镜检查显示，Δhbx1突变体不产生分生孢子梗。Δhbx1突变体不能产生分生孢子与分生孢子梗发育的调控基因brlA（刚毛）和abaA（算盘）的下调有关。这些突变体还使黄曲霉毒素途径生物合成基因aflC、aflD、aflM以及簇特异性调控基因aflR显著下调。我们的结果表明，hbx1不仅在控制黄曲霉发育方面起着重要作用，而且对次生代谢产物（如黄曲霉毒素）的产生也至关重要。
Homeobox proteins, a class of well conserved transcription factors, regulate the expression of targeted genes, especially those involved in development. In filamentous fungi, homeobox genes are required for normal conidiogenesis and fruiting body formation. In the present study, we identified eight homeobox (hbx) genes in the aflatoxin-producing ascomycete, Aspergillus flavus, and determined their respective role in growth, conidiation and sclerotial production. Disruption of seven of the eight genes had little to no effect on fungal growth and development. However, disruption of the homeobox gene AFLA_069100, designated as hbx1, in two morphologically different A. flavus strains, CA14 and AF70, resulted in complete loss of production of conidia and sclerotia as well as aflatoxins B1 and B2, cyclopiazonic acid and aflatrem. Microscopic examination showed that the Δhbx1 mutants did not produce conidiophores. The inability of Δhbx1 mutants to produce conidia was related to downregulation of brlA (bristle) and abaA (abacus), regulatory genes for conidiophore development. These mutants also had significant downregulation of the aflatoxin pathway biosynthetic genes aflC, aflD, aflM and the cluster-specific regulatory gene, aflR. Our results demonstrate that hbx1 not only plays a significant role in controlling A. flavus development but is also critical for the production of secondary metabolites, such as aflatoxins.
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影响因子：
5.2
作者：
Calvo AM;Cary JW
通讯作者：
Cary JW
影响因子：
3.7
作者：
Coppin E;Berteaux-Lecellier V;Bidard F;Brun S;Ruprich-Robert G;Espagne E;Aït-Benkhali J;Goarin A;Nesseir A;Planamente S;Debuchy R;Silar P
通讯作者：
Silar P
影响因子：
4.4
作者：
CHANG, PK;CARY, JW;PAYNE, GA
通讯作者：
PAYNE, GA
影响因子：
4.4
作者：
Chang, Perng-Kuang;Scharfenstein, Leslie L.;Ehrlich, Kenneth C.
通讯作者：
Ehrlich, Kenneth C.
影响因子：
4.5
作者：
Sarikaya Bayram O;Bayram O;Valerius O;Park HS;Irniger S;Gerke J;Ni M;Han KH;Yu JH;Braus GH
通讯作者：
Braus GH