Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, 36050, Guanajuato, Guanajuato, Mexico.
Antonie Van Leeuwenhoek. 2021 May;114(5):609-624. doi: 10.1007/s10482-021-01545-3. Epub 2021 Mar 3.
It is well documented that disturbance of cell surface by some agents triggers compensatory responses aimed to maintain the cell wall integrity in fungi and other organisms. Here, the thermodimorphic fungus Sporothrix globosa, a member of the pathogenic clade of the Sporothrix complex, was propagated in yeast-peptone-dextrose medium under conditions to obtain the mycelium (pH 4.5, 27-28 °C) or the yeast (pH 7.8, 32-34 °C) morphotypes in the absence and presence of the wall-interacting dyes Congo Red (CR) and Calcofluor White (CFW) either alone or in combination. After different periods of time, growth, cell morphology and activity of glucosamine-6-phosphate synthase (GlcN-6-P synthase), an ubiquitous enzyme that plays a crucial role in cell wall biogenesis, were determined. CR and to a lower extent CFW affected growth and morphology of both fungal morphotypes and significantly increased enzyme activity. Notoriously, CR or CR in combination with CFW induced the transient conversion of yeasts into conidia-forming filamentous cells even under culture conditions adjusted for yeast development, most likely as a strategy to evade the noxious effect of the dye. After sometime, hypha returned to yeast cells. An hypothetical model to explain the effect of CR on morphology and enzyme activity based on the possible role of membrane-spanning proteins known as mechanosensors is proposed. Results are discussed in terms of the fungal responses to cell wall damage.
有大量文献记载，某些药剂会扰乱细胞表面，从而引发补偿性反应，以维持真菌和其他生物的细胞壁完整性。在这里，我们选择热双相真菌 S. globosa 作为研究对象，它是引发孢子丝菌病的致病枝孢霉复合体中的一员。我们在酵母-蛋白胨-葡萄糖培养基中，于不同条件下对其进行培养，以便获得菌丝（pH4.5，27-28°C）或酵母（pH7.8，32-34°C）形态，同时，在不存在或存在细胞壁相互作用染料刚果红（CR）和钙荧光素白（CFW）的情况下，分别单独或联合使用这些染料。经过不同的时间后，我们测定了生长情况、细胞形态和葡萄糖胺-6-磷酸合酶（GlcN-6-P 合酶）的活性，这种酶是一种普遍存在的酶，在细胞壁生物合成中起着至关重要的作用。结果表明，CR 和在一定程度上 CFW 会影响两种真菌形态的生长和形态，并且会显著增加酶的活性。值得注意的是，即使在调整为适合酵母发育的培养条件下，CR 或 CR 与 CFW 的联合使用也会诱导酵母短暂地转化为形成分生孢子的丝状细胞，这很可能是一种逃避染料毒害的策略。一段时间后，菌丝又会变回酵母细胞。基于已知的膜跨膜蛋白（称为机械感受器）的可能作用，我们提出了一个假设模型来解释 CR 对形态和酶活性的影响。我们根据细胞壁损伤对真菌的响应来讨论这些结果。
