植物抗坏血酸的生物合成、转运及其生物学功能

抗坏血酸是高等植物中普遍存在的小分子物质，在植物细胞对氧化胁迫的抵抗、细胞分裂和伸长中发挥着重要作用。它在线粒体中合成，然后被转运到其他细胞区间以发挥生理作用。在不同生物膜上可能存在不同的ASC转运体，这些转运体的存在可使ASC及其不同氧化还原态形式根据细胞生理状况的需要而在不同细胞区间转运。ASC的重要生理功能是与其氧化还原状态以及生物合成、代谢、再生和转运的相关酶类活性的变化密切相关的。本文简要综述了近年来人们在植物抗坏血酸生物合成、代谢、转运、逆境响应与植物生长发育中的研究进展。

Biosynthesis,transport and function of ascorbate in plants

Ascorbate (ASC) is a major metabolite in higher plants and present in different cell compartments of cells. At a physiological level, ASC participates in a scavenging pathway of reactive oxygen species in the chloroplast known as the ascorbate-glutathione cycle. In addition, ASC also fulfils essential roles in plant growth, development and defense outside the chloroplast. Despite its importance in plant biology, the pathway of ASC biosynthesis has only recently been elucidated. ASC is synthesized in the mitochondria and must be transported to other cellular compartments to function its biological roles. Regulation of ASC transport systems may be central in the regulation of different physiological processes including progression through the cell cycle, expansion of the cell wall and defense against abiotic and biotic stresses.