Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia; Proteomics International, Nedlands, WA, Australia.
Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia.
J Proteomics. 2022 Oct 30;269:104725. doi: 10.1016/j.jprot.2022.104725. Epub 2022 Sep 10.
Phytopathogenic oomycetes pose a significant threat to global biodiversity and food security. The proteomes of these oomycetes likely contain important factors that contribute to their pathogenic success, making their discovery crucial for elucidating pathogenicity. Phytophthora cinnamomi is a root pathogen that causes dieback in a wide variety of crops and native vegetation world-wide. Virulence proteins produced by P. cinnamomi are not well defined and a large-scale approach to understand the biochemistry of this pathogen has not been documented. Soluble mycelial, zoospore and secreted proteomes were obtained and label-free quantitative proteomics was used to compare the composition of the three sub-proteomes. A total of 4635 proteins were identified, validating 17.7% of the predicted gene set. The mycelia were abundant in transporters for nutrient acquisition, metabolism and cellular proliferation. The zoospores had less metabolic related ontologies but were abundant in energy generating, motility and signalling associated proteins. Virulence-associated proteins were identified in the secretome such as candidate effector and effector-like proteins, which interfere with the host immune system. These include hydrolases, cell wall degrading enzymes, putative necrosis-inducing proteins and elicitins. The secretome elicited a hypersensitive response on the roots of a model host and thus suggests evidence of effector activity. SIGNIFICANCE: Phytophthora cinnamomi is a phytopathogenic oomycete that causes dieback disease in native vegetation and several horticultural crops such as avocado, pineapple and macadamia. Whilst this pathogen has significance world-wide, its pathogenicity and virulence have not been described in depth. We carried out comparative label-free proteomics of the mycelia, zoospores and secretome of P. cinnamomi. This study highlights the differential metabolism and cellular processes between the sub-proteomes. Proteins associated with metabolism, nutrient transport and cellular proliferation were over represented in the mycelia. The zoospores have a specialised proteome showing increased energy generation geared towards motility. Candidate effectors and effector-like secreted proteins were also identified, which can be exploited for genetic resistance. This demonstrates a better understanding of the biology and pathogenicity of P. cinnamomi infection that can subsequently be used to develop effective methods of disease management.
植物病原卵菌对全球生物多样性和粮食安全构成重大威胁。这些卵菌的蛋白质组可能包含有助于其致病成功的重要因素，因此发现这些因素对于阐明致病性至关重要。肉桂疫霉是一种根病原体，可导致全球各种作物和本地植被的枯萎病。肉桂疫霉产生的毒力蛋白尚未得到很好的定义，也没有记录大规模了解这种病原体生物化学的方法。获得了可溶菌丝体、游动孢子和分泌的蛋白质组，并使用无标记定量蛋白质组学来比较这三个亚蛋白质组的组成。总共鉴定了 4635 种蛋白质，验证了预测基因集的 17.7%。菌丝体富含营养物质获取、代谢和细胞增殖的转运蛋白。游动孢子的代谢相关本体论较少，但富含能量生成、运动和信号相关蛋白。在分泌液中鉴定出了与毒力相关的蛋白质，如候选效应子和效应子样蛋白，它们会干扰宿主的免疫系统。其中包括水解酶、细胞壁降解酶、假定的坏死诱导蛋白和 elicitins。分泌液在模式宿主的根部引起过敏反应，因此表明存在效应子活性的证据。意义：肉桂疫霉是一种植物病原卵菌，可导致本地植被和几种园艺作物（如鳄梨、菠萝和澳洲坚果）发生枯萎病。尽管该病原体在全球范围内具有重要意义，但它的致病性和毒力尚未得到深入描述。我们对肉桂疫霉的菌丝体、游动孢子和分泌液进行了比较无标记蛋白质组学分析。这项研究强调了亚蛋白质组之间的差异代谢和细胞过程。与代谢、营养物质运输和细胞增殖相关的蛋白质在菌丝体中过量表达。游动孢子具有专门的蛋白质组，显示出增加的能量生成，以适应运动。还鉴定了候选效应子和效应子样分泌蛋白，可用于遗传抗性。这表明对肉桂疫霉感染的生物学和致病性有了更好的理解，随后可以用于开发有效的疾病管理方法。
