frustules Lignin lignified oocyst mycoplasmas sporangial polysaccharides arabinogalactan suberin sporopollenin xyloglucan rhamnose invaginations cell runcinated glycoproteins phagosome pectin phosphodiester nucleocapsid plasmalemma callose phragmosome preprophase tracheids mineraloid nucleolus procollagen caucanus endodermal cellulose Heparan phragmoplast phosphoglycerides Sirai polysaccharide oligosaccharides covalently glycocalyx