Semighini Camile P, Hornby Jacob M, Dumitru Raluca, Nickerson Kenneth W, Harris Steven D
Plant Science Initiative, University of Nebraska Lincoln, Lincoln, NE, USA.
Mol Microbiol. 2006 Feb;59(3):753-64. doi: 10.1111/j.1365-2958.2005.04976.x.
The dimorphic fungus Candida albicans secretes farnesol, which acts as a quorum-sensing molecule and prevents the yeast to mycelium conversion. In this study we examined the effect of farnesol in the filamentous fungus Aspergillus nidulans. We show that externally added farnesol has no effect on hyphal morphogenesis; instead, it triggers morphological features characteristic of apoptosis. Additional experiments suggest that mitochondria and reactive oxygen species (ROS) participate in farnesol-induced apoptosis. Moreover, the effects of farnesol appear to be mediated by the FadA heterotrimeric G protein complex. Because A. nidulans does not secrete detectable amounts of farnesol, we propose that it responds to farnesol produced by other fungi. In agreement with this notion, growth and development were impaired in a farnesol-dependent manner when A. nidulans was co-cultivated with C. albicans. Taken together, our data suggest that farnesol, in addition to its quorum-sensing function that regulates morphogenesis, is also employed by C. albicans to reduce competition from other microbes.
二态真菌白色念珠菌分泌法尼醇，法尼醇作为一种群体感应分子，可阻止酵母向菌丝体的转变。在本研究中，我们检测了法尼醇对丝状真菌构巢曲霉的影响。我们发现，外源添加的法尼醇对菌丝形态发生没有影响；相反，它会引发凋亡的特征性形态学特征。进一步的实验表明，线粒体和活性氧（ROS）参与了法尼醇诱导的凋亡。此外，法尼醇的作用似乎是由FadA异源三聚体G蛋白复合体介导的。由于构巢曲霉不分泌可检测量的法尼醇，我们推测它对其他真菌产生的法尼醇有反应。与此观点一致的是，当构巢曲霉与白色念珠菌共培养时，其生长和发育以法尼醇依赖的方式受到损害。综上所述，我们的数据表明法尼醇除了具有调节形态发生的群体感应功能外，白色念珠菌还利用它来减少来自其他微生物的竞争。
