hemicellulose
Hemicellulose is a class of branched heteropolymers, including arabinoxylans and xyloglucans, that form a major structural component of plant cell walls alongside cellulose and lignin. Unlike the rigid crystalline structure of cellulose, hemicelluloses are more flexible and interact with other cell wall components to modulate wall strength, porosity, and extensibility. Understanding hemicellulose composition and remodeling is central to research on plant growth, development, and the engineering of biomass for biofuel and industrial applications.
open_in_new WikipediaPubMed · 2026-04-01
Scientists discovered that certain enzymes inside plant cells — previously thought only to break down cell wall sugars outside the cell — actually help build those same sugars in the first place. This finding reveals a hidden step in how plants construct their cell walls, which could unlock new ways to engineer stronger or more useful plant materials.
Two mannan-degrading enzymes (MAN2 and MAN5) were found to operate inside the Golgi apparatus — the cell's internal assembly factory — rather than only outside the cell as previously assumed.
Arabidopsis plants lacking both MAN2 and MAN5 produced seeds that looked like mutants unable to make mannan at all, linking these 'degrading' enzymes directly to mannan production.
In yeast experiments, intracellular MAN2 and MAN5 converted insoluble mannan into water-soluble forms, suggesting they help keep the biosynthesis process flowing by preventing clogging with insoluble material.