Convergent Emergence of Glucomannan β-Galactosyltransferase Activity in Asterids and Rosids.

β-Galactoglucomannan (β-GGM) is a primary cell wall polysaccharide in rosids and asterids. The β-GGM polymer has a backbone of repeating β-(1,4)-glucosyl and mannosyl residues, usually with mono-α-(1,6)-galactosyl substitution or β-(1,2)-galactosyl α-galactosyl disaccharide side chains on the mannosyl residues. Mannan β-galactosyltransferases (MBGTs) are therefore required for β-GGM synthesis.

Expression of laccase and ascorbate oxidase affects lignin composition in Arabidopsis thaliana stems.

Lignin is a phenolic polymer that is a major source of biomass. Oxidative enzymes, such as laccase and peroxidase, are required for lignin polymerisation. Laccase is a member of the multicopper oxidase family and has a high amino acid sequence similarity with ascorbate oxidase.

Reciprocal regulation of cellulose and lignin biosynthesis by the transcription factor OsTCP19.

This article comments on: Lv S, Lin Z, Shen J, Luo L, Xu Q, Li L, Gui J. 2024. coordinates inhibition of lignin biosynthesis and promotion of cellulose biosynthesis to modify lodging resistance in rice.

Differing structures of galactoglucomannan in eudicots and non-eudicot angiosperms.

The structures of cell wall mannan hemicelluloses have changed during plant evolution. Recently, a new structure called β-galactoglucomannan (β-GGM) was discovered in eudicot plants. This galactoglucomannan has β-(1,2)-Gal-α-(1,6)-Gal disaccharide branches on some mannosyl residues of the strictly alternating Glc-Man backbone.

The function of the plant cell wall in plant-microbe interactions.

The plant cell wall is an interface of plant-microbe interactions. The ability of microbes to decompose cell wall polysaccharides contributes to microbial pathogenicity. Plants have evolved mechanisms to prevent cell wall degradation.

Eudicot primary cell wall glucomannan is related in synthesis, structure, and function to xyloglucan.

Hemicellulose polysaccharides influence assembly and properties of the plant primary cell wall (PCW), perhaps by interacting with cellulose to affect the deposition and bundling of cellulose fibrils. However, the functional differences between plant cell wall hemicelluloses such as glucomannan, xylan, and xyloglucan (XyG) remain unclear. As the most abundant hemicellulose, XyG is considered important in eudicot PCWs, but plants devoid of XyG show relatively mild phenotypes.

Reconsidering the function of the xyloglucan endotransglucosylase/hydrolase family.

Plants possess an outer cell layer called the cell wall. This matrix comprises various molecules, such as polysaccharides and proteins, and serves a wide array of physiologically important functions. This structure is not static but rather flexible in response to the environment.