Hempel Priscilla P, Keffer Jessica L, Maresca Julia A
Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States.
Department of Civil and Environmental Engineering, University of Delaware, Newark, DE, United States.
Front Microbiol. 2021 Nov 1;12:739005. doi: 10.3389/fmicb.2021.739005. eCollection 2021.
Light is a ubiquitous source of both energy and information in surface environments, and regulates gene expression not only in photosynthetic microorganisms, but in a broad range of photoheterotrophic and heterotrophic microbes as well. Actinobacteria are keystone species in surface freshwater environments, where the ability to sense light could allow them to coordinate periods of nutrient uptake and metabolic activity with primary production. The model freshwater Actinobacteria () strain MWH-Ta8 and () strain MWH-Mo1 grow faster in the light than in the dark, but do not use light energy to support growth. Here, we characterize transcription throughout a light-dark cycle in and . In both species, some genes encoding carbohydrate metabolism and storage are upregulated in the light. However, expression of genes of the TCA cycle is only coordinated with light availability in In fact, the majority of genes that respond to light and darkness in these two species are different, even though their light-responsive phenotypes are similar. The ability to respond to light and darkness may be widespread in freshwater Actinobacteria, but the genetic networks controlled by these two stimuli may vary significantly.
光在地表环境中是一种无处不在的能量和信息源,它不仅能调节光合微生物的基因表达,还能调节多种光能异养和异养微生物的基因表达。放线菌是地表淡水环境中的关键物种,在这类环境中,感知光的能力可以使它们将养分吸收和代谢活动的时间段与初级生产协调起来。典型的淡水放线菌()菌株MWH-Ta8和()菌株MWH-Mo1在光照下比在黑暗中生长得更快,但并不利用光能来支持生长。在这里,我们对和在一个明暗循环中的转录情况进行了表征。在这两个物种中,一些编码碳水化合物代谢和储存的基因在光照下会上调。然而,三羧酸循环相关基因的表达仅在中与光照可用性相协调。实际上,尽管这两个物种对光和暗的反应表型相似,但它们中大多数对光和暗作出反应的基因是不同的。对光和暗作出反应的能力可能在淡水放线菌中广泛存在,但由这两种刺激所控制的基因网络可能有很大差异。