Schwarz Rakefet, Forchhammer Karl
Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel.
Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany.
Microbiology (Reading). 2005 Aug;151(Pt 8):2503-2514. doi: 10.1099/mic.0.27883-0.
Cyanobacteria are equipped with numerous mechanisms that allow them to survive under conditions of nutrient starvation, some of which are unique to these organisms. This review surveys the molecular mechanisms underlying acclimation responses to nitrogen and phosphorus deprivation, with an emphasis on non-diazotrophic freshwater cyanobacteria. As documented for other micro-organisms, nutrient limitation of cyanobacteria elicits both general and specific responses. The general responses occur under any starvation condition and are the result of the stresses imposed by arrested anabolism. In contrast, the specific responses are acclimation processes that occur as a result of limitation for a particular nutrient; they lead to modification of metabolic and physiological routes to compensate for the restriction. First, the general acclimation processes are discussed, with an emphasis on modifications of the photosynthetic apparatus. The molecular mechanisms underlying specific responses to phosphorus and nitrogen-limitation are then outlined, and finally the cross-talk between pathways modulating specific and general responses is described.
蓝藻具备多种机制，使其能够在营养饥饿条件下生存，其中一些机制是这些生物所特有的。本综述探讨了蓝藻对氮和磷缺乏的适应反应背后的分子机制，重点关注非固氮淡水蓝藻。正如其他微生物的情况一样，蓝藻的营养限制会引发一般反应和特定反应。一般反应在任何饥饿条件下都会发生，是合成代谢停滞所施加压力的结果。相比之下，特定反应是由于特定营养素限制而发生的适应过程；它们导致代谢和生理途径的改变，以补偿这种限制。首先，讨论一般适应过程，重点是光合装置的改变。然后概述对磷和氮限制的特定反应背后的分子机制，最后描述调节特定反应和一般反应的途径之间的相互作用。
