果胶的生物学特性和功能功能分析.pdf

Plant Molecular Biology 47: 9–27, 2001. 9 © 2001 Kluwer Academic Publishers. Printed in the Netherlands. Pectin: cell biology and prospects for functional analysis 1 1 2 1,∗ William G.T. Willats , Lesley McCartney , William Mackie and J. Paul Knox 1Centre for Plant Sciences and 2School of Biochemistry Molecular Biology, University of Leeds, Leeds LS2 9JT, UK (∗author for correspondence; e-mail j.p.knox@leeds.ac.uk) Key words: cell wall, homogalacturonan, pectin, pectinases, polysaccharide, rhamnogalacturonan Abstract Pectin is a major component of primary cell walls of all land plants and encompasses a range of galacturonic acid-rich polysaccharides. Three major pectic polysaccharides (homogalacturonan, rhamnogalacturonan-I and rhamnogalacturonan-II) are thought to occur in all primary cell walls. This review surveys what is known about the structure and function of these pectin domains. The high degree of structural complexity and heterogeneity of the pectic matrix is produced both during biosynthesis in the endomembrane system and as a result of the action of an array of wall-based pectin-modifying enzymes. Recent developments in analytical techniques and in the generation of anti-pectin probes have begun to place the structural complexity of pectin in cell biological and developmental contexts. The in muro de-methyl-esterification of homogalacturonan by pectin methyl esterases is emerging as a key process for the local modulation of matrix properties. Rhamnogalacturonan-I comprises a highly diverse population of spatially and developmentally regulated polymers, whereas rhamnogalacturonan-II appears to be a highly conserved and stable pectic domain. Current knowledge of biosynthetic enzymes, plant and