Angiosperms, cell-wall

Condensed or catechin tannins (catechol tannins. Fig. 11.3) are the most common tannins in vascular plants, occurring in three quarters of gym-nosperms and over half of the angiosperms. They are unbranched, linear polymers of flavonoid compounds (flavan-3-ols), linked through acid-labile carbon-carbon bonds. Condensed tannins may protect plant cell walls against microbial attack and so may affect microbial fermentation of plant cell walls in herbivores. 

Cell walls of woods contain other subgroups of hemicelluloses, in particular those composed primarily of D-mannopyranosyl or D-galactopyranosyl units. Glucomannans [11078-31-2] comprise 3—5% of the wood of angiosperms and 3—12% of the wood of gymnosperms. Galactoglucomannans... 

In by far the greater number of Angiosperms, the endosperm nucleus, after double fertilization, divides and redivides, giving rise to numerous nuclei imbedded in the protoplasm of the embryo sac, outside of the developing embryo. Gathering protoplasm about themselves and laying down cell walls they form the endosperm tissue outside of the embryo. Into this tissue food is passed constituting the Endospermic albumen. 

Component of Ghamnogalacturonan II of angiosperms and gymnosperms, cell wall of Tetraselnius striata and gram-negative Rhizobiaceae bacteria. 

Naim C.J. and Haselkom T. (2005). Three loblolly pine CesA genes expressed in developing xylem are orthologous to secondary cell wall CesA genes of angiosperms. New Phytol. 166 907-915. 

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