Universidade do Vale do Paraíba, São José dos Campos, SP, 12244-000, Brazil.
Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP, 12602-810, Brazil.
Fungal Biol. 2020 May;124(5):273-288. doi: 10.1016/j.funbio.2019.09.001. Epub 2019 Sep 16.
Osmotic stress induced by high solute concentration can prevent fungal metabolism and growth due to alterations in properties of the cytosol, changes in turgor, and the energy required to synthesize and retain compatible solutes. We used germination to quantify tolerance/sensitivity to the osmolyte KCl (0.1-4.5 M, in 0.1 M increments) for 71 strains (40 species) of ecologically diverse fungi. These include 11 saprotrophic species (17 strains, including two xerophilic species), five mycoparasitic species (five strains), six plant-pathogenic species (13 strains), and 19 entomopathogenic species (36 strains). A dendrogram obtained from cluster analyses, based on KCl inhibitory concentrations 50 % and 90 % calculated by Probit Analysis, revealed three groups of fungal isolates accordingly to their osmotolerance. The most-osmotolerant group (Group 3) contained the majority of saprotrophic fungi, and Aspergillus niger (F19) was the most tolerant. The highly xerophilic Aspergillus montevidense and Aspergillus pseudoglaucus were the second- and third-most tolerant species, respectively. All Aspergillus and Cladosporium species belonged to Group 3, followed by the entomopathogens Colletotrichum fioriniae, Simplicillium lanosoniveum, and Trichothecium roseum. Group 2 exhibited a moderate osmotolerance, and included plant-pathogens such as Colletotrichum and Fusarium, mycoparasites such as Clonostachys spp, some saprotrophs such as Mucor and Penicillium spp., and some entomopathogens such as Isaria, Lecanicillium, Mariannaea, Simplicillium, and Torrubiella. Group 1 contained the osmo-sensitive strains: the rest of the entomopathogens and the mycoparasitic Gliocladium and Trichoderma. Although stress tolerance did not correlate with their primary ecological niche, classification of these 71 fungal strains was more closely aligned with their ecology than with their phylogenetic relatedness. We discuss the implications for both microbial ecology and fungal taxonomy.
高渗透压会导致胞质溶胶性质改变、膨压变化以及合成和保留相容溶质所需的能量改变，从而抑制真菌的新陈代谢和生长。我们使用萌发的方法，量化了 71 株（40 个种）生态多样性真菌对渗透压溶质 KCl（0.1-4.5 M，每隔 0.1 M 递增）的耐受/敏感性。这些真菌包括 11 种腐生种（17 株，包括两种嗜干种）、5 种菌寄生种（5 株）、6 种植物病原种（13 株）和 19 种昆虫病原种（36 株）。根据 Probit 分析计算的 KCl 抑制浓度 50%和 90%，通过聚类分析得到的系统发育树显示，真菌分离株根据其耐渗透压能力分为三组。最耐渗透压的一组（第 3 组）包含了大多数腐生真菌，黑曲霉（F19）是最耐受的。高度嗜干的曲霉属菌（A. montevidense 和 A. pseudoglaucus）分别是第二和第三最耐受的种。所有的曲霉菌和枝孢菌都属于第 3 组，其次是昆虫病原真菌 C. fioriniae、S. lanosoniveum 和 T. roseum。第 2 组表现出中等耐渗透压能力，包括植物病原真菌（如胶孢炭疽菌和镰刀菌）、菌寄生真菌（如棒束孢属）、一些腐生真菌（如毛霉和青霉）和一些昆虫病原真菌（如棒束孢菌、淡紫拟青霉、金龟子绿僵菌、丝核菌、栓菌和弯颈霉）。第 1 组包含渗透压敏感菌株：其余的昆虫病原真菌和菌寄生真菌Gliocladium 和 Trichoderma。尽管应激耐受力与它们的主要生态位无关，但这 71 株真菌的分类与它们的生态学比与它们的系统发育关系更密切。我们讨论了这对微生物生态学和真菌分类学的影响。
