title: Homogalacturonan-modifying enzymes: structure, expression, and roles in plants.
abstract: Understanding the changes affecting the plant cell wall is a key element in addressing its functional role in plant growth and in the response to stress. Pectins, which are the main constituents of the primary cell wall in dicot species, play a central role in the control of cellular adhesion and thereby of the rheological properties of the wall. This is likely to be a major determinant of plant growth. How the discrete changes in pectin structure are mediated is thus a key issue in our understanding of plant development and plant responses to changes in the environment. In particular, understanding the remodelling of homogalacturonan (HG), the most abundant pectic polymer, by specific enzymes is a current challenge in addressing its fundamental role. HG, a polymer that can be methylesterified or acetylated, can be modified by HGMEs (HG-modifying enzymes) which all belong to large multigenic families in all species sequenced to date. In particular, both the degrees of substitution (methylesterification and/or acetylation) and polymerization can be controlled by specific enzymes such as pectin methylesterases (PMEs), pectin acetylesterases (PAEs), polygalacturonases (PGs), or pectate lyases-like (PLLs). Major advances in the biochemical and functional characterization of these enzymes have been made over the last 10 years. This review aims to provide a comprehensive, up to date summary of the recent data concerning the structure, regulation, and function of these fascinating enzymes in plant development and in response to biotic stresses.
authors: EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France.
authors: Fabien
authors: F
authors: Sénéchal
authors: EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France.
authors: Christopher
authors: C
authors: Wattier
authors: EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France.
authors: Christine
authors: C
authors: Rustérucci
authors: EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France jerome.pelloux@u-picardie.fr.
authors: Jérôme
authors: J
authors: Pelloux
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D004950:Esterases / Q000378:metabolism; D008970:Molecular Weight; D010368:Pectins / Q000378:metabolism*; D011096:Polygalacturonase / Q000378:metabolism
chemical_list: D010368:Pectins; D004950:Esterases; D002265:Carboxylic Ester Hydrolases; C100533:pectinacetylesterase; C022323:pectinesterase; D011096:Polygalacturonase; C003181:polygalacturonic acid
keywords: Biotic stress; development; homogalacturonans; pectate lyase-like; pectin methylesterase; pectins; polygalacturonase.