Loss of bcbrn1 and bcpks13 in Botrytis cinerea Not Only Blocks Melanization But Also Increases Vegetative Growth and Virulence.
Loss of bcbrn1 and bcpks13 in Botrytis cinerea Not Only Blocks Melanization But Also Increases Vegetative Growth and Virulence.
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DOI：
10.1094/mpmi-04-15-0085-r
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发表时间：
2015-09
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影响因子：
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通讯作者：
Chenghua Zhang;Yifan He;Pinkuan Zhu;Lu Chen;Yiwen Wang;B. Ni;Ling Xu
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作者：
Chenghua Zhang;Yifan He;Pinkuan Zhu;Lu Chen;Yiwen Wang;B. Ni;Ling Xu
灰葡萄孢是一种坏死营养型病原体，在广泛的植物中引起灰霉病。二羟基萘（DHN）黑色素是B细胞外基质的主要成分。灰霉病，但黑色素生物合成在这种病原体中的确切作用的知识还不清楚。在这项研究中，我们描述了两个基因在B。cinerea，bcpks13和bcbrn1，分别编码聚酮合酶和四羟基萘（THN）还原酶，并且两者都在DHN黑色素生物合成中具有预测的作用。该突变体的spanbcpks13和spanbcbrn1分别显示白色和橙子色素沉着，和突变体也缺乏在体外分生孢子，但显示增强的生长速度和对宿主的毒性。此外，突变体显示完全培养基（CM）的酸化升高，这可能是由于草酸分泌和细胞壁降解酶的分泌，并且优选地利用植物细胞壁组分作为体外菌丝体生长的碳源。相反，bcbrn1（OE：：bcbrn1菌株）的过表达导致水解酶分泌、酸化能力和毒力减弱。综上所述，这些结果表明，bcpks 13和bcbrn 1参与不同的细胞和发育过程，如黑化和分生孢子在B。灰霉病菌在体外，但他们负调节这种病原体的毒力。
Botrytis cinerea is a necrotrophic pathogen that causes gray mold disease in a broad range of plants. Dihydroxynaphthalene (DHN) melanin is a major component of the extracellular matrix of B. cinerea, but knowledge of the exact role of melanin biosynthesis in this pathogen is unclear. In this study, we characterize two genes in B. cinerea, bcpks13 and bcbrn1, encoding polyketide synthase and tetrahydroxynaphthalene (THN) reductases, respectively, and both have predicted roles in DHN melanin biosynthesis. The ∆bcpks13 and ∆bcbrn1 mutants show white and orange pigmentation, respectively, and the mutants are also deficient in conidiation in vitro but show enhanced growth rates and virulence on hosts. Moreover, the mutants display elevated acidification of the complete medium (CM), probably due to oxalic acid secretion and secretion of cell wall-degrading enzymes, and preferably utilize plant cell-wall components as carbon sources for mycelium growth in vitro. In contrast, overexpression of bcbrn1 (OE::bcbrn1 strain) results in attenuated hydrolytic enzyme secretion, acidification ability, and virulence. Taken together, these results indicate that bcpks13 and bcbrn1 participate in diverse cellular and developmental processes, such as melanization and conidiation in B. cinerea in vitro, but they negatively regulate the virulence of this pathogen.