Arabinogalactan proteins in root and pollen-tube cells: distribution and functional aspects
Abstract
Arabinogalactan proteins (AGPs) are complex proteoglycans of the cell wall found in the entire
plant kingdom and in almost all plant organs. AGPs encompass a large group of heavily glycosylated cellwall proteins which share common features, including the presence of glycan chains especially enriched in arabinose and galactose and a protein backbone particularly rich in hydroxyproline residues. However, AGPs also
exhibit strong heterogeneities among their members in various plant species. AGP ubiquity in plants suggests
these proteoglycans are fundamental players for plant survival and development.
Scope In this review, we first present an overview of current knowledge and specific features of AGPs. A section
devoted to major tools used to study AGPs is also presented. We then discuss the distribution of AGPs as well as
various aspects of their functional properties in root tissues and pollen tubes. This review also suggests novel
directions of research on the role of AGPs in the biology of roots and pollen tubes.