Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA.
Int J Mol Sci. 2019 Sep 5;20(18):4363. doi: 10.3390/ijms20184363.
Crassulacean acid metabolism (CAM) is characterized by nocturnal CO uptake and concentration, reduced photorespiration, and increased water-use efficiency (WUE) when compared to C and C plants. Plants can perform different types of CAM and the magnitude and duration of CAM expression can change based upon several abiotic conditions, including nutrient availability. Here, we summarize the abiotic factors that are associated with an increase in CAM expression with an emphasis on the relationship between CAM photosynthesis and nutrient availability, with particular focus on nitrogen, phosphorus, potassium, and calcium. Additionally, we examine nitrogen uptake and assimilation as this macronutrient has received the greatest amount of attention in studies using CAM species. We also discuss the preference of CAM species for different organic and inorganic sources of nitrogen, including nitrate, ammonium, glutamine, and urea. Lastly, we make recommendations for future research areas to better understand the relationship between macronutrients and CAM and how their interaction might improve nutrient and water-use efficiency in order to increase the growth and yield of CAM plants, especially CAM crops that may become increasingly important as global climate change continues.
景天酸代谢（CAM）的特点是夜间 CO 吸收和浓缩，与 C3 和 C4 植物相比，减少了光呼吸，提高了水分利用效率（WUE）。植物可以进行不同类型的 CAM，CAM 表达的幅度和持续时间可以根据包括养分供应在内的几种非生物条件而变化。在这里，我们总结了与 CAM 表达增加相关的非生物因素，重点介绍了 CAM 光合作用与养分供应之间的关系，特别关注氮、磷、钾和钙。此外，我们还研究了氮的吸收和同化，因为在使用 CAM 物种的研究中，这种大量营养素受到了最多的关注。我们还讨论了 CAM 物种对不同有机和无机氮源的偏好，包括硝酸盐、铵盐、谷氨酰胺和尿素。最后，我们提出了未来研究领域的建议，以更好地了解大量营养素和 CAM 之间的关系，以及它们的相互作用如何提高养分和水的利用效率，从而增加 CAM 植物的生长和产量，特别是随着全球气候变化的继续，CAM 作物可能会变得越来越重要。
