DHN melanin biosynthesis in the plant pathogenic fungus Botrytis cinerea is based on two developmentally regulated key enzyme (PKS)-encoding genes
DHN melanin biosynthesis in the plant pathogenic fungus Botrytis cinerea is based on two developmentally regulated key enzyme (PKS)-encoding genes
复制标题
DOI：
10.1111/mmi.13262
复制
发表时间：
2016-02-01
影响因子：
3.6
通讯作者：
Schumacher, Julia
中科院分区：
文献类型：
--
作者：
Schumacher, Julia
灰葡萄孢是各种植物物种中灰霉病的病原体，并且在感染周期结束时产生灰色大分生孢子和/或黑色菌核。据认为，色素沉着是由于1，8-二羟基萘（DHN）黑色素的积累。为了阐明其基础和调控，推定的黑素生成和调控基因进行了鉴定和功能表征。与其他DHN黑色素产生菌不同，B.灰霉病菌和其它Leotiomycetes含有两种关键酶（PKS）编码酶。bcpks 12和bcpks 13是发育调控的，分别是菌核和分生孢子中黑素生成所必需的。BcYGH 1转化BcPKS 13产物，从而有助于分生孢子黑素生成。相反，作用于PKS产物（BcBRN 2、BcSCD 1和BcBRN 1）转化下游的酶是菌核和分生孢子黑素生成所需的，表明DHN黑素生成在B中。灰葡萄糖遵循非线性途径，这对于次级代谢途径是相当不寻常的。黑素生成基因的调控涉及三种途径特异性转录因子（TF），它们与bcpks 12或bcpks 13和其他发育调节因子（如光响应TF）聚在一起。黑素基因被保存在营养菌丝体中，以保证其正常生长和毒力。然而，DHN黑色素被认为有助于生殖结构的寿命。
Botrytis cinerea is the causal agent of gray mold disease in various plant species and produces grayish macroconidia and/or black sclerotia at the end of the infection cycle. It has been suggested that the pigmentation is due to the accumulation of 1,8-dihydroxynaphthalene (DHN) melanin. To unravel its basis and regulation, the putative melanogenic and regulatory genes were identified and functionally characterized. Unlike other DHN melanin-producing fungi, B. cinerea and other Leotiomycetes contain two key enzyme (PKS)-encoding enzymes. Bcpks12 and bcpks13 are developmentally regulated and are required for melanogenesis in sclerotia and conidia respectively. BcYGH1 converts the BcPKS13 product and contributes thereby to conidial melanogenesis. In contrast, enzymes acting downstream in conversion of the PKS products (BcBRN2, BcSCD1 and BcBRN1) are required for both, sclerotial and conidial melanogenesis, suggesting that DHN melanogenesis in B. cinerea follows a non-linear pathway that is rather unusual for secondary metabolic pathways. Regulation of the melanogenic genes involves three pathway-specific transcription factors (TFs) that are clustered with bcpks12 or bcpks13 and other developmental regulators such as light-responsive TFs. Melanogenic genes are dispensable in vegetative mycelia for proper growth and virulence. However, DHN melanin is considered to contribute to the longevity of the reproduction structures.