College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Fisheries College, Jimei University, Xiamen 361021, China.
Mar Drugs. 2021 Nov 26;19(12):664. doi: 10.3390/md19120664.
Floridean starch and floridoside are the main storage carbohydrates of red algae. However, their complete metabolic pathways and the origin, function, and regulatory mechanism of their pathway genes have not been fully elucidated. In this study, we identified their metabolic pathway genes and analyzed the changes in related gene expression and metabolite content in under continuous dark conditions. Our results showed that genes from different sources, including eukaryotic hosts, cyanobacteria, and bacteria, were combined to construct floridean starch and floridoside metabolic pathways in . Moreover, compared with those in the control, under continuous dark conditions, floridean starch biosynthesis genes and some degradation genes were significantly upregulated with no significant change in floridean starch content, whereas floridoside degradation genes were significantly upregulated with a significant decrease in floridoside content. This implies that floridean starch content is maintained but floridoside is consumed in under dark conditions. This study elucidates the "floridean starch-floridoside" metabolic network and its gene origins in for the first time.
红藻的主要储存碳水化合物是叶托藻淀粉和叶托藻糖苷。然而，它们完整的代谢途径以及其途径基因的起源、功能和调控机制尚未完全阐明。在本研究中，我们鉴定了它们的代谢途径基因，并分析了在持续黑暗条件下 中相关基因表达和代谢物含量的变化。我们的结果表明，来自不同来源的基因，包括真核宿主、蓝藻和细菌，被组合在一起，在 中构建了叶托藻淀粉和叶托藻糖苷代谢途径。此外，与对照组相比，在持续黑暗条件下，叶托藻淀粉生物合成基因和一些降解基因显著上调，而叶托藻淀粉含量没有明显变化，而叶托藻糖苷降解基因显著上调，叶托藻糖苷含量明显下降。这表明在黑暗条件下， 中维持叶托藻淀粉含量但消耗叶托藻糖苷。本研究首次阐明了 中“叶托藻淀粉-叶托藻糖苷”代谢网络及其基因起源。
