Structural diversity, functions and biosynthesis of xyloglucans in angiosperm cell walls.

• Xyloglucans occur in the primary cell walls of all angiosperms where they are thought to have a structural role and be involved in the control of cell expansion. They also occur in the thick, non-lignified secondary cell walls of seeds of some species ofeudicotyledons where they serve as reserve carbohydrates. The xyloglucans in the primary cell walls of most eudicotyledons have similar structures with side chains containing galactose and fucose. However, in one group of eudicotyledons, the asterids, there is considerable structural variability in the xyloglucans, with many containing arabinose. There is also variability in the xyloglucans of the monocotyledons, with those in the family Poaceae containing no fucose and only small proportions ofgalactose. The xyloglucans of the thick, secondary cell walls of seeds are similar to those in the primary walls of most eudicotyledons, but contain no fucose. The functional significance of these structural variations is unknown. A number of genes and their encoded glycosyltransferases have been identified as being involved in the biosynthesis of the xyloglucans of the model eudicotyledon Arabidopsis thaliana. 

Ämnesord

LANTBRUKSVETENSKAPER  -- Lantbruksvetenskap, skogsbruk och fiske -- Skogsvetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Agriculture, Forestry and Fisheries -- Forest Science (hsv//eng)

Nyckelord

Cell expansion

Eudicotyledons

Grasses and cereals (poaceae)

Monocotyledons

Primary cell walls

Seed cell walls

Xyloglucan biosynthesis

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ref (ämneskategori)

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