Schiller Katharina, Janshoff Saskia, Zenker Sanja, Viehöver Prisca, Hartwell James, Eirich Jürgen, Finkemeier Iris, Bräutigam Andrea
Computational Biology, Bielefeld University, 33615 Bielefeld, Germany.
Center for Biotechnology, CeBiTec Bielefeld, 33615 Bielefeld, Germany.
Plant Physiol. 2025 Mar 28;197(4). doi: 10.1093/plphys/kiaf095.
Crassulacean acid metabolism (CAM) is an adaptation to environments where water availability is seasonal or extremely low. It serves to ensure plant survival and/or maintain productivity in these adverse environments. CAM has repeatedly evolved in many plant lineages, although it requires a large and complex set of enzymes, transporters, and regulatory processes to control metabolite flux and pools. To test the potential levels at which CAM is regulated, we analyzed the CAM plant Kalanchoë laxiflora and compared with the genomes and transcriptomes of other CAM plants across a wide phylogenetic range. We show that CAM-associated transcripts and proteins did not exhibit a binary on/off pattern in abundance between day and night in K. laxiflora. Instead, K. laxiflora and many CAM plants displayed shared amino acid changes among proteins compared to C3 plants, especially in starch metabolism. Phosphoproteomics identified differential phosphorylation in K. laxiflora proteins between day and night. Taken together, our results demonstrate that CAM photosynthesis is regulated at both the transcript and protein levels.
景天酸代谢（CAM）是植物对季节性缺水或极端干旱环境的一种适应性机制。它有助于确保植物在这些恶劣环境中存活和/或维持生产力。尽管景天酸代谢需要大量复杂的酶、转运蛋白以及调控过程来控制代谢物通量和库，但它在许多植物谱系中反复进化。为了测试景天酸代谢的潜在调控水平，我们分析了CAM植物长花伽蓝菜，并与广泛系统发育范围内的其他CAM植物的基因组和转录组进行了比较。我们发现，在长花伽蓝菜中，与景天酸代谢相关的转录本和蛋白质在白天和夜晚的丰度并没有呈现出二元的开/关模式。相反，与C3植物相比，长花伽蓝菜和许多CAM植物在蛋白质中表现出共同的氨基酸变化，尤其是在淀粉代谢方面。磷酸化蛋白质组学鉴定出长花伽蓝菜蛋白质在白天和夜晚存在差异磷酸化。综合来看，我们的结果表明景天酸代谢光合作用在转录和蛋白质水平上均受到调控。
