Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, China.
J Proteomics. 2020 Jun 15;221:103776. doi: 10.1016/j.jprot.2020.103776. Epub 2020 Apr 5.
Phytophthora sojae is a widely distributed, destructive oomycete plant pathogen that has been developed as a model for oomycete biology. Given the important but limited reports on the comparison of the sexual and asexual stages in Phytophthora, we performed a large-scale quantitative proteomics study on two key asexual life stages of P. sojae-the mycelium and cyst-as well as on the oospore, which is a key sexual stage. Over 29,631 peptides from 4688 proteins were analyzed. Briefly, 445 proteins, 624 proteins, and 579 proteins were defined as differentially quantified proteins in cyst vs mycelium, oospore vs cyst, and oospore vs mycelium comparisons, respectively (|log2 fold change| > 1 and P < 0.05). Compared to the mycelium and oospore, fatty acid and nitrogen metabolism were specifically induced in cysts. In oospores, the up-regulated proteins focused on RNA transport and protein processing in endoplasmic reticulum, indicating translation, folding, and the secretion of core cellular or stage-specific proteins active in oospores, which might be used for oospore germination. The data presented expand our knowledge of pathways specifically linked to asexual and sexual stages of this pathogen. BIOLOGICAL SIGNIFICANCE: The sexual spores (oospores) in oomycetes have thick cell walls and can survive in the soil for years, thus providing a primary source and allowing the reinfection of their host plant in subsequent growing seasons. However, the proteomic study on oospores remains very limited as they are generally considered to be dormant. In the present study, we successfully isolated oospores, and performed a large-scale comparative quantitative proteomics study on this key sexual stage and two representative asexual stages of P. sojae. The results provide an improved understanding of P. sojae biology and suggest potential metabolic targets for disease control at the three different developmental stages in oomycetes.
大豆疫霉是一种分布广泛、具有破坏性的卵菌植物病原体，已被开发为卵菌生物学的模式生物。鉴于关于卵菌有性和无性阶段比较的报道非常有限，我们对大豆疫霉的两个关键无性生活阶段——菌丝和游动孢子囊，以及作为关键有性阶段的卵孢子，进行了大规模的定量蛋白质组学研究。从 4688 种蛋白质中分析了超过 29631 种肽。简要地说，游动孢子囊与菌丝相比、卵孢子与游动孢子囊相比、卵孢子与菌丝相比，分别有 445 种、624 种和 579 种蛋白质被定义为差异定量蛋白（|log2 倍变化|>1 和 P<0.05）。与菌丝和卵孢子相比，脂肪酸和氮代谢在游动孢子囊中特异性地被诱导。在卵孢子中，上调的蛋白质集中在内质网中的 RNA 转运和蛋白质加工上，表明翻译、折叠和核心细胞或阶段特异性蛋白质在卵孢子中的分泌，这些蛋白质可能用于卵孢子萌发。所提供的数据扩展了我们对该病原体无性和有性阶段特定途径的认识。生物学意义：卵菌中的有性孢子（卵孢子）具有厚的细胞壁，可以在土壤中存活多年，因此为其宿主植物在随后的生长季节再次感染提供了主要来源。然而，卵孢子的蛋白质组学研究仍然非常有限，因为它们通常被认为是休眠的。在本研究中，我们成功地分离了卵孢子，并对大豆疫霉的这一关键有性阶段和两个有代表性的无性阶段进行了大规模的比较定量蛋白质组学研究。结果提高了对大豆疫霉生物学的认识，并为卵菌三个不同发育阶段的病害控制提供了潜在的代谢靶标。
