硅藻具有形态各异、结构复杂、精美绝伦的硅质细胞壁,是海洋中进行生物硅化最主要的生物体。硅质细胞壁的形成同样是一个错综复杂的过程,它涉及硅藻细胞将硅酸从胞外转运到胞内;硅酸在细胞内的转移;在硅沉积囊泡(SDV)中的浓缩沉积;最后合成具种类特异性的细胞壁。重点介绍硅酸转运基因(SITs)的分子特征与作用机制;与生物硅化相关的三种蛋白即硅体蛋白(frus-tulins)、亲硅蛋白(silaffins)和侧壁蛋白(pleuralins)的结构与功能;硅质结构如何在硅沉积囊泡内最终形成的模式。
Diatoms have different morphologies,structure complex and beautiful silica cell wall.They are one of the largest groups of silicifying organisms in the ocean.The genetic control and mechanism of this silica structure formation are a very complicated process,including silica acid transportation across biological membranes to cells,silica acid transformation inside cells,silica polymerization within silica deposition vesicle(SDV),and formation of species-specific cell wall and complex silica structure.An overview of current knowledge about the diatom silica structure formation in recent years was provided.It is focused on the detailed structure and function of silica acid transporters(SITs),three proteins associated with biomineralization-frustulins,silaffins and pleuralins,and the mode of the frustule formation inside SDV.