Shao Zhanru, Duan Delin
CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.
Front Plant Sci. 2022 May 10;13:902823. doi: 10.3389/fpls.2022.902823. eCollection 2022.
Cell wall polysaccharides (CWPS) of seaweeds play crucial roles in mechanical shear resistance, cell-cell adhesion and the interactions with changeable marine environments. They have diverse applications in food, cosmetics, agriculture, pharmaceuticals and therapeutics. The recent boost of multi-omics sequence analysis has rapidly progressed the mining of presumed genes encoding enzymes involved in CWPS biosynthesis pathways. In this review, we summarize the biosynthetic pathways of alginate, fucoidan, agar, carrageenan and ulvan in seaweeds referred to the literatures on published genomes and biochemical characterization of encoded enzymes. Some transcriptomic data were briefly reported to discuss the correlation between gene expression levels and CWPS contents. Mannuronan C-5 epimerase (MC5E) and carbohydrate sulfotransferase (CST) are crucial enzymes for alginate and sulfated CWPS, respectively. Nonetheless, most CWPS-relevant genes were merely investigated by gene mining and phylogenetic analysis. We offer an integrative view of CWPS biosynthesis from a molecular perspective and discuss about the underlying regulation mechanism. However, a clear understanding of the relationship between chemical structure and bioactivities of CWPS is limited, and reverse genetic manipulation and effective gene editing tools need to be developed in future.
海藻的细胞壁多糖（CWPS）在抗机械剪切、细胞间粘附以及与多变海洋环境的相互作用中发挥着关键作用。它们在食品、化妆品、农业、制药和治疗等领域有着广泛应用。近期多组学序列分析的发展迅速推动了对参与CWPS生物合成途径的假定编码酶基因的挖掘。在这篇综述中，我们参考已发表基因组的文献以及所编码酶的生化特性总结了海藻中藻酸盐、岩藻依聚糖、琼脂、卡拉胶和昆布多糖的生物合成途径。简要报道了一些转录组数据以讨论基因表达水平与CWPS含量之间的相关性。甘露糖醛酸C-5差向异构酶（MC5E）和碳水化合物硫酸转移酶（CST）分别是藻酸盐和硫酸化CWPS的关键酶。尽管如此，大多数与CWPS相关的基因仅通过基因挖掘和系统发育分析进行了研究。我们从分子角度提供了CWPS生物合成的综合观点，并讨论了潜在的调控机制。然而，对CWPS化学结构与生物活性之间关系的清晰理解仍然有限，未来需要开发反向遗传操作和有效的基因编辑工具。
