Cellulose synthesis: mutational analysis and genomic perspectives using Arabidopsis thaliana

Abstract

Cellulose microfibrils containing crystalline beta-1,4-glucan provide the major structural framework in higher-plant cell walls. Genetic analyses of Arabidopsis thaliana now link specific genes to plant cellulose production just as was achieved some years earlier with bacteria. Cellulose-deficient mutants have defects in several members of one family within a complex glycosyltransferase superfamily and in one member of a small family of membrane-bound endo-1,4-beta-glucanases. The mutants also accumulate a readily extractable beta-1,4-glucan that has short chains which, in at least one case, are lipid linked. Cellulose could be made by direct extension of the glucan chain by the glycosyltransferase or, as the mutant suggests, by an indirect route which makes lipid-linked oligosaccharides. Models discussed incorporate the known enzymes and lipo-glucan and raise the possibility that different CesA glycosyltransferases may catalyse different steps.

Subfunctionalization of Cellulose Synthases in Seed Coat Epidermal Cells Mediates Secondary Radial Wall Synthesis and Mucilage Attachment

“…Observations were made in seeds isolated from whole siliques 10 d post anthesis (DPA) from transgenic plants. Cell shape and morphogenesis are partially reliant upon cellulose biosynthesis in various cell types (Brown, 1985;Williamson et al, 2001;Desprez et al, 2002). Based on seed coat preferential gene expression, we next used genetics to investigate whether CESA2, CESA5, and/or CESA9 were required for normal morphogenesis of the seed epidermal cells.…”

Evolutionary and functional implications of the complex glycosylation of Skp1, a cytoplasmic/nuclear glycoprotein associated with polyubiquitination

“…For example, in prokaryotes, precursors for the peptidoglycan, lipooligosaccharide and capsule are initially glycosylated at the cytoplasmic surface of the plasma membrane and subsequently flipped to the cell surface [67,68]. The polysaccharides cellulose, hyaluronan and chondroitin are translocated across the plasma membrane as they are polymerized [49,69]. In eukaryotes, precursors for Nglycan biosynthesis and early intermediates in GPI-anchor synthesis and glycolipid synthesis are similarly flipped into the rER or Golgi interiors, and cellulose, chitin and hyaluronan are synthesized as in prokaryotes ( fig.…”

Molecular Analysis of a Family of Arabidopsis Genes Related to Galacturonosyltransferases

“…The synthesis of these polysaccharides requires a significant commitment of the plant's genomic resources; perhaps as many as 10% of genes in Arabidopsis (Arabidopsis thaliana) have been estimated to be involved in plant cell wall synthesis, maintenance, modification, and degradation (Carpita et al, 2001). Many of these genes belong to multigene families (Henrissat et al, 2001) whose individual members have distinct patterns of expression among plant cells and tissues (Taylor et al, 1999(Taylor et al, , 2000Fagard et al, 2000;Peng et al, 2000;Sarria et al, 2001;Williamson et al, 2001;Orfila et al, 2005;Burton et al, 2006;Harholt et al, 2006;Peñ a et al, 2007;Persson et al, 2007). At least 50 glycosyltransferases (GTs) are predicted to be required for pectin synthesis (Ridley et al, 2001).…”