细胞孢菌是一种破坏性的植物病原真菌,在许多木本植物上引起溃疡病。然而,关于c.chrysosperma和它的宿主之间的相互作用的知识仍然有限。植物病原体产生的次生代谢产物通常在其毒力中起重要作用。萜烯环化酶(TC),聚酮合成酶(PKS)和非核糖体肽合成酶(NRPS)是次生代谢产物合成的关键组分。这里,我们表征了推定的萜烯型次生代谢产物生物合成核心基因CcPtc1在C.chrysosperma中的功能,在感染早期显著上调。重要的是,与野生型(WT)菌株相比,CcPtc1的缺失大大降低了对杨树树枝的真菌毒力,并且还显示出显着降低的真菌生长和分生孢子。此外,对每个菌株的粗提物进行的毒性试验表明,与WT菌株相比,ΔCcPtc1分泌的粗提物的毒性受到了严重破坏。随后,进行了ΔCcPtc1突变体和WT菌株之间的非靶向代谢组学分析,与WT菌株相比,ΔCcPtc1突变体中的193种显着不同的丰富代谢物(DAMs),包括90个显著下调的代谢物和103个显著上调的代谢物,分别。其中,四个关键的代谢途径,据报道是重要的真菌毒力被富集,包括泛酸和辅酶A(CoA)的生物合成。此外,我们还检测到一系列萜类化合物的显著改变,其中(+)-ar-姜黄酮,pulegone,菊花酸乙酯,京尼平显著下调,而对苯醛和(±)-脱落酸显著上调。总之,我们的研究结果表明,CcPtc1是一种毒力相关的次级代谢因子,并提供了对C.chrysosperma发病机制的新见解.
Cytospora chrysosperma is a destructive plant pathogenic fungus, which causes canker disease on numerous woody plants. However, knowledge concerning the interaction between C. chrysosperma and its host remains limited. Secondary metabolites produced by phytopathogens often play important roles in their virulence. Terpene cyclases (TC), polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) are the key components for the synthesis of secondary metabolites. Here, we characterized the functions of a putative terpene type secondary metabolite biosynthetic core gene CcPtc1 in C. chrysosperma, which was significantly up-regulated in the early stages of infection. Importantly, deletion of CcPtc1 greatly reduced fungal virulence to the poplar twigs and they also showed significantly reduced fungal growth and conidiation compared with the wild-type (WT) strain. Furthermore, toxicity test of the crude extraction from each strain showed that the toxicity of crude extraction secreted by ΔCcPtc1 were strongly compromised in comparison with the WT strain. Subsequently, the untargeted metabolomics analyses between ΔCcPtc1 mutant and WT strain were conducted, which revealed 193 significantly different abundant metabolites (DAMs) inΔCcPtc1 mutant compared to the WT strain, including 90 significantly downregulated metabolites and 103 significantly up-regulated metabolites, respectively. Among them, four key metabolic pathways that reported to be important for fungal virulence were enriched, including pantothenate and coenzyme A (CoA) biosynthesis. Moreover, we also detected significant alterations in a series of terpenoids, among which (+)-ar-turmerone, pulegone, ethyl chrysanthemumate, and genipin were significantly down-regulated, while cuminaldehyde and (±)-abscisic acid were significantly up-regulated. In conclusion, our results demonstrated that CcPtc1 acts as a virulence-related secondary metabolism factor and provides new insights into the pathogenesis of C. chrysosperma.