Arabinogalactan proteins in root and pollen-tube cells: distribution and functional aspects

International audienceArabinogalactan proteins (AGPs) are complex proteoglycans of the cell wall found in the entireplant 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 alsoexhibit strong heterogeneities among their members in various plant species. AGP ubiquity in plants suggeststhese 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 sectiondevoted to major tools used to study AGPs is also presented. We then discuss the distribution of AGPs as well asvarious aspects of their functional properties in root tissues and pollen tubes. This review also suggests noveldirections of research on the role of AGPs in the biology of roots and pollen tubes