Pectic polysaccharides are an essential component of the primary plant cell wall. They are particularly prominent in pollen tubes, where they control the structure and yielding characteristics of the cell wall at the growing apex of these rapidly expanding cells. The properties of pectin meshworks, to a considerable degree, are regulated by postsecretory changes resulting from the activity of c...

Pectic polysaccharides are an essential component of the primary plant cell wall. They are particularly prominent in pollen tubes, where they control the structure and yielding characteristics of the cell wall at the growing apex of these rapidly expanding cells. The properties of pectin meshworks, to a considerable degree, are regulated by postsecretory changes resulting from the activity of c...

Pectinases constitute a group of enzymes that act on pectic substances, acid polysaccharides present in the primary wall of plants. Pectinases are used in the food industry, in the processing of fruits, in pulp maceration, in the extraction and clarification of juices and in the wine industry. The juice extraction is carried out, generally, by the pressing and partial destruction of the pectin ...

The out genes of the enterobacterial plant pathogen Erwinia chrysanthemi are responsible for the efficient extracellular secretion of multiple plant cell wall-degrading enzymes, including four isozymes of pectate lyase, exo-poly-alpha-D-galacturonosidase, pectin methylesterase, and cellulase. Out- mutants of Er. chrysanthemi are unable to export any of these proteins beyond the periplasm and ar...

l-Rhamnose is a component of plant cell wall pectic polysaccharides, diverse secondary metabolites, and some glycoproteins. The biosynthesis of the activated nucleotide-sugar form(s) of rhamnose utilized by the various rhamnosyltransferases is still elusive, and no plant enzymes involved in their synthesis have been purified. In contrast, two genes (rmlC and rmlD) have been identified in bacter...

This paper describes electron microscopic studies on the distribution of pectin within young plant cells. Dark-grown onion roots, from 1 to 3 mm. in length, were used. In order to make the pectic substances selectively dense to electrons, they were first reacted with basic hydroxylamine. This treatment produces pectic hydroxamic acids, which in turn were treated with ferric ion to form insolubl...

BACKGROUND Inefficient carbohydrate conversion has been an unsolved problem for various lignocellulosic biomass pretreatment technologies, including AFEX, dilute acid, and ionic liquid pretreatments. Previous work has shown 22% of total carbohydrates are typically unconverted, remaining as soluble or insoluble oligomers after hydrolysis (72 h) with excess commercial enzyme loading (20 mg enzyme...

Ethylene supplied with indoleacetic acid at 0.1 and 1 mum inhibited elongation and enhanced swelling in epicotyls of decapitated and derooted pea seedlings (Pisum sativum L., var. Alaska). These growth responses were correlated with the development of cell walls rich in weak acid-extractable materials and pectic uronic acids. Ethylene had no effect on the formation of hemicellulose, or hemicell...