高等植物花色苷的液泡摄取机制(英文)

Vacuolar sequestration mechanisms of anthocyanins in higher plants

关键词:  高等植物  花色苷  液泡摄取  机制

Key words:  higher plants  anthocyanins  vacuolar sequestration  mechanisms

摘要:

综述了高等植物细胞中花色苷被液泡摄取的机制。花色苷通过细胞质中定位于粗糙内质网细胞质面的多酶复合体合成后被膜包裹形成囊泡。这些囊泡主要向液泡移动,在移动中相互融合形成更大囊泡,最终将花色苷带到液泡膜的表面。在大多数情况下,花色苷经过液泡膜上的各种载体被迅速运进液泡。另外两种较少的是:(1)囊泡直接与液泡融合;(2)液泡膜自主形成大的管状内陷,使囊泡在内陷处指向液泡内腔“发芽”。在上述种种可能的具体过程中,花色苷以非修饰或修饰两种形式被摄入液泡。花色苷跨液泡膜运送可能通过4种模型实现,即由ATP结合盒型的载体介导、由依赖pH梯度的载体介导、由24-kD液泡蛋白前体衍生的蛋白质介导和由多重药物和有毒化合物排出家族的载体介导。据推测,不同植物利用不同的摄取机制将花色苷积累在液泡中,而多重机制也可能被单个植物种同时使用。

Abstract:

This review sumed up the mechanisms of anthocyanins being sequestered into vacuole in the cells of higher plants. After being synthesized by the multienzyme complexes locating at the cytoplasmic face of the rough endoplasmic reticulum in the cytoplasm,anthocyanins are enwrapped by membrane to form vesicles which migrate mainly toward the vacuole,coalesce each other to form larger vesicles in the migration,and ultimately bring the anthocyanins to the surface of the tonoplast. In most cases,anthocyanins are expeditiously transported into vacuole by various transporters locating on the tonoplast. Other two minor possibilities are that:(1)the vesicles fuse directly with the vacuole;(2)the tonoplast may independently form a large tubular invagination from which the vesicles“bud off”into the vacuole lumen. In the concrete courses of above possibilities,anthocyanins are sequestrated into vacuole in two forms,namely non-modified and modified. The transtonoplast transport of anthocyanins may be accomplished by four models,namely mediated by ATP-binding cassette(ABC)type transporter,by pH-dependent transporter,by the proteins derived from the 24-kD vacuolar protein(VP24)precursor and by multidrug and toxic compound extrusion(MATE)family transporter. It is speculated that different plant species utilize different sequestration mechanisms to accumulate anthocyanins in vacuole,and multiple mechanisms may be simultaneously used in individual plant species.