Grossman Arthur, Takahashi Hideki
Department of Plant Biology, The Carnegie Institution of Washington 260 Panama Street, Stanford, California 94305; e-mail:
Annu Rev Plant Physiol Plant Mol Biol. 2001 Jun;52:163-210. doi: 10.1146/annurev.arplant.52.1.163.
Organisms acclimate to a continually fluctuating nutrient environment. Acclimation involves responses specific for the limiting nutrient as well as responses that are more general and occur when an organism experiences different stress conditions. Specific responses enable organisms to efficiently scavenge the limiting nutrient and may involve the induction of high-affinity transport systems and the synthesis of hydrolytic enzymes that facilitate the release of the nutrient from extracellular organic molecules or from internal reserves. General responses include changes in cell division rates and global alterations in metabolic activities. In photosynthetic organisms there must be precise regulation of photosynthetic activity since when severe nutrient limitation prevents continued cell growth, excitation of photosynthetic pigments could result in the formation of reactive oxygen species, which can severely damage structural and functional features of the cell. This review focuses on ways that photosynthetic eukaryotes assimilate the macronutrients nitrogen, sulfur, and phosphorus, and the mechanisms that govern assimilatory activities. Also discussed are molecular responses to macronutrient limitation and the elicitation of those responses through integration of environmental and cellular cues.
生物体适应不断波动的营养环境。适应包括针对限制性营养物质的特异性反应，以及更普遍的反应，这些反应在生物体经历不同应激条件时发生。特异性反应使生物体能够有效地摄取限制性营养物质，可能涉及诱导高亲和力转运系统以及合成水解酶，这些水解酶有助于从细胞外有机分子或内部储备中释放营养物质。普遍反应包括细胞分裂速率的变化和代谢活动的整体改变。在光合生物中，必须对光合活性进行精确调节，因为当严重的营养限制阻止细胞持续生长时，光合色素的激发可能导致活性氧的形成，这会严重损害细胞的结构和功能特征。本综述重点关注光合真核生物吸收大量营养元素氮、硫和磷的方式，以及控制同化活动的机制。还讨论了对大量营养元素限制的分子反应以及通过整合环境和细胞信号引发这些反应的过程。
