College of Agriculture, Shihezi University and Key Laboratory at Universities of Xinjiang Uygur Autonomous Region for Oasis Agricultural Pest Management and Plant Protection Resource Utilization, Shihezi, 832003, China.
State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
Sci China Life Sci. 2017 Aug;60(8):868-879. doi: 10.1007/s11427-017-9075-3. Epub 2017 Jul 26.
Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form of melanized microsclerotia. To investigate the melanin synthesis in V. dahliae, we identified a polyketide synthase gene in V. dahliae, namely VdPKS1. PKS1 is known to involve in the dihydroxynaphthalene melanin synthesis pathway in many fungi. We found that VdPKS1 was required for melanin formation but not for microsclerotial production in V. dahliae. The VdPKS1 gene-disruption mutant (vdpks1) formed melanin-deficient albino microsclerotia, which did not affect the fungal colonization in host tissues but significantly reduced the disease severity. Gene transcription analysis in the wild-type and the vdpks1 strains suggested that VdPKS1 gene-disruption influenced the expression of a series of genes involved in ethylene biosynthesis, microsclerotial formation and pathogenesis. Our results suggest that the VdPKS1-mediated melanin synthesis is important for virulence and developmental traits of V. dahliae.
黄萎轮枝菌是一种土壤传播的植物病原真菌，可引起广泛宿主的维管束萎蔫病。该病原体以黑化小菌核的形式在土壤中存活多年。为了研究黄萎轮枝菌中的黑色素合成，我们在黄萎轮枝菌中鉴定了一个聚酮合酶基因，即 VdPKS1。众所周知，PKS1 参与许多真菌中的二羟基萘黑色素合成途径。我们发现 VdPKS1 对于黑色素的形成是必需的，但对于黄萎轮枝菌中小菌核的产生不是必需的。VdPKS1 基因敲除突变体（vdpks1）形成黑色素缺陷的白化小菌核，这不会影响真菌在宿主组织中的定殖，但显著降低了疾病严重程度。在野生型和 vdpks1 菌株中的基因转录分析表明，VdPKS1 基因敲除影响了一系列参与乙烯生物合成、小菌核形成和致病过程的基因的表达。我们的结果表明，VdPKS1 介导的黑色素合成对于黄萎轮枝菌的毒力和发育特性很重要。
