CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative-UMR 7238, Sorbonne Université, 4 place Jussieu , 75005 Paris, France.
Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS,INSERM, Université PSL , Paris 75005, France.
Philos Trans R Soc Lond B Biol Sci. 2024 Nov 18;379(1914):20230354. doi: 10.1098/rstb.2023.0354. Epub 2024 Sep 30.
Vitamin B, also known as cobalamin, is an essential organic cofactor for methionine synthase (METH), and is only synthesized by a subset of bacteria. Plants and fungi have an alternative methionine synthase (METE) that does not need B and are typically considered not to utilize it. Some algae facultatively utilize B because they encode both METE and METH, while other algae are dependent on B as they encode METH only. We performed phylogenomic analyses of METE, METH and 11 further proteins involved in B metabolism across more than 1600 plant and algal genomes and transcriptomes (e.g. from OneKp), demonstrating the presence of B-associated metabolism deep into the streptophytes. METH and five further accessory proteins (MTRR, CblB, CblC, CblD and CblJ) were detected in the hornworts (Anthocerotophyta), and two (CblB and CblJ) were identified in liverworts (Marchantiophyta) in the bryophytes, suggesting a retention of B-metabolism in the last common land plant ancestor. Our data further show more limited distributions for other B-related proteins (MCM and RNR-II) and B dependency in several algal orders. Finally, considering the collection sites of algae that have lost B metabolism, we propose freshwater-to-land transitions and symbiotic associations to have been constraining factors for B availability in early plant evolution. This article is part of the theme issue 'The evolution of plant metabolism'.
维生素 B，也称为钴胺素，是甲硫氨酸合成酶（METH）的必需有机辅因子，仅由一部分细菌合成。植物和真菌有替代的甲硫氨酸合成酶（METE），不需要 B，通常被认为不利用它。一些藻类兼性利用 B，因为它们编码 METE 和 METH，而其他藻类则依赖 B，因为它们只编码 METH。我们对超过 1600 个植物和藻类基因组和转录组中的 METE、METH 和 11 种进一步参与 B 代谢的蛋白质进行了系统发育基因组分析（例如来自 OneKp），证明 B 相关代谢存在于 Streptophytes 中。METH 和另外五个辅助蛋白（MTRR、CblB、CblC、CblD 和 CblJ）在角苔（Anthocerotophyta）中被检测到，在苔藓植物（Marchantiophyta）中，两个（CblB 和 CblJ）被鉴定出来，这表明 B 代谢在最后一个共同的陆地植物祖先中得以保留。我们的数据还进一步显示，其他 B 相关蛋白（MCM 和 RNR-II）和几个藻类目在 B 依赖性方面的分布更为有限。最后，考虑到失去 B 代谢的藻类的采集地点，我们提出淡水到陆地的过渡和共生关系是早期植物进化中 B 可用性的限制因素。本文是主题为“植物代谢的进化”的特刊的一部分。
