On the Separate Metabolisms of UDP-Sugars and GDP-Sugars in Plants

Abstract

UDP-sugars and GDP-sugars serve as substrates in the synthesis of numerous polysaccharides. Conversions of monosaccharides to other monosaccharides often occur by way of nucleotide sugars. Certain toxic monosaccharides such as D-galactose are metabolized into non-toxic sugars via nucleotide sugars. The sugar species largely determines whether a sugar is metabolized as a UDP- or GDP-sugar and these two types of nucleotide sugars follow metabolic pathways, which are, as it turns out, basically independent. In this paper, we outline the metabolic pathways of nucleotide sugars in plants and discuss the physiological importance and mechanisms for the separate metabolic pathways.