Cellulose and Callose Biosynthesis in Higher Plants (I. Solubilization and Separation of (1->3)- and (1->4)-β-Glucan Synthase Activities from Mung Bean)

Abstract

(1 +3)-and (1 +4)-P-glucan synthase activities from higher plants have been physically separated by gel electrophoresis in nondenaturing conditions. The two glucan synthases show different mobilities i n native polyacrylamide gels. Further separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a different polypeptide composition i n these synthases. Three polypeptides (64, 54, and 32 kD) seem to be common to both synthase activities, whereas two polypeptides (78 and 38 kD) are associated only with callose synthase activity. Twelve polypeptides (1 70, 136,108, 96, 83, 72,66, 60, 52, 48,42, and 34 kD) appear to be specifically associated with cellulose synthase activity. The successful separation of (1 -3)-and (1 ++p-glucan synthase activities was based on the manipulation of digitonin concentrations used in the solubilization of membrane proteins. At low dipitomin concentrations (0.05 and 0.1 %), the ratio of the cellulose to callose synthase activity was higher. At higher digitonin (0.5-1 %) concentrations, the ratio of the callose to cellulose synthase activity was higher. Rosette-like particles with attached product were observed in samples taken from the top of the stacking gel, where only cellulose was synthesized. Smaller (nonrosette) particles were found i n the running gel, where only callose was synthesized. These findings suggest that a higher leve1 of subunit organization is required for i n vitro cellulose synthesis in comparison with callose assembly.

Immunogold Labeling of Rosette Terminal Cellulose-Synthesizing Complexes in the Vascular Plant Vigna angularis

“…Independently, Arioli et al (1998) found the same gene using an Arabidopsis mutant. Kudlicka and Brown (1997) reported the separation of ␤ -1,3-and ␤ -1,4-glucan synthase activities using gel electrophoresis in nondenaturing conditions. These gels could be incubated in UDP-glucose and the resulting in vitro products visualized with the electron microscope.…”

Novelties of the flowering plant pollen tube underlie diversification of a key life history stage

“…This unique pollen tube wall structure is thought to allow faster growth rates than possible in other tip-growing cells because (i) the pectic tip is more plastic and rapidly extensible, (ii) the mature tube cell wall has greater resistance to tension stress because of deesterification of pectins and secretion of callose, and (iii) callose plugs help maintain positive turgor pressure in the growing tip (27,31). There is evidence that building an amorphous callose-based wall is faster and more energy efficient than biosynthesis of a cellulose microfibril-based wall (29,32). Furthermore, silencing of genes involved in either pectin modification or callose synthesis reduces pollen competitive ability (33-35).…”

Tools for Cellulose Analysis in Plant Cell Walls

“…The first successful in vitro synthesis of cellulose from plant cell-free extracts was achieved using cotton fiber and mung bean (Vigna radiata) enzymes (Kudlicka et al, 1995(Kudlicka et al, , 1996Kudlicka and Brown, 1997). However, it was only several years later that the amount of cellulose synthesized in vitro was significantly improved by the careful selection of detergents that allow the extraction of enzyme complexes in an intact form (Lai Kee Him et al, 2002).…”