Chitinase

About: Chitinase is a research topic. Over the lifetime, 4690 publications have been published within this topic receiving 161786 citations. The topic is also known as: 1,4-beta-poly-N-acetylglucosaminidase & poly-beta-glucosaminidase.

Molecular cloning and characterization of chitinase genes from Streptomyces lividans 66

Abstract: Summary: In order to study the genetic control of chitinolytic activity in Streptomyces, chitinase genes were cloned from S. lividans TK64 into the multicopy plasmid pIJ702 and their expression monitored in their natural host by measuring increases in chitinase productivity. Four independent clones were obtained, and the plasmids named pEMJ1, pEMJ5, pEMJ7 and pEMJ8. Restriction endonuclease digestion showed that although two of the plasmids (pEMJ7 and pEMJ8) shared a common DNA fragment, there were no substantial similarities between the inserts of plasmids pEMJ1, pEMJ5 and pEMJ7. This was confirmed by DNA-DNA hybridization studies. Four chitinases (A, B, C, and D) were identified, with molecular masses of 36, 46, 65, and 41 kDa, respectively. Production of chitinases A and B was specified by the plasmids pEMJ1 and pEMJ5, respectively. Genes for the other two chitinases (C and D) were carried by plasmid pEMJ7. Although significant differences were observed between chitinases A, B, and C in terms of optimum pH for activity and mode of digestion of substrates, chitinases C and D were very similar in these respects. Cloned genes were also expressed in S. coelicolor M130 and in Escherichia coli.

Biological control of Botrytis cinerea by selected grapevine-associated bacteria and stimulation of chitinase and β-1,3 glucanase activities under field conditions

Abstract: In this study, the biocontrol ability of seven grapevine-associated bacteria, previously reported as efficient against Botrytis cinerea under in vitro conditions, was evaluated in two vineyard orchards with the susceptible cv Chardonnay during four consecutive years (2002–2005) It was shown that the severity of disease on grapevine leaves and berries was reduced to different levels, depending on the bacterial strain and inoculation method Drenching the plant soil with these bacteria revealed a systemic resistance to B cinerea, even without renewal of treatment Accordingly, this resistance was associated with a stimulation of some plant defense responses such as chitinase and β-1,3-glucanase activities in both leaves and berries In leaves, chitinase activity increased before veraison (end-July) while β-1,3-glucanase reached its maximum activity at ripening (September) Reverse patterns were observed in berries, with β-1,3-glucanase peaking at full veraison (end-August) and chitinase at a later development stage Highest activities were observed with Acinetobacter lwoffii PTA-113 and Pseudomonas fluorescens PTA-CT2 in leaves, and with A lwoffii PTA-113 and Pantoea agglomerans PTA-AF1 in berries These results have demonstrated an induced protection of grapevine against B cinerea by selected bacteria under field conditions, and suggest that induced resistance could be related to a stimulation of plant defense reactions in a successive manner

Biological Control of Sclerotium rolfsii and Verticillium dahliae by Talaromyces flavus Is Mediated by Different Mechanisms.

Abstract: Ten wild-type strains and two benomyl-resistant mutants of Talaromyces flavus were examined for their ability to secrete the cell wall-degrading enzymes chitinase, beta-1,3-glucanase, and cellulase, to parasitize sclerotia of Sclerotium rolfsii, to reduce bean stem rot caused by S. rolfsii, and to secrete antifungal substance(s) active against Verticillium dahliae. The benomyl-resistant mutant Ben(R)TF1-R6 overproduced extracellular enzymes and exhibited enhanced antagonistic activity against S. rolfsii and V. dahliae compared to the wild-type strains and other mu tants. Correlation analyses between the extracellular enzymatic activities of different isolates of T. flavus and their ability to antagonize S. rolfsii indicated that mycoparasitism by T. flavus and biological control of S rolfsii were related to the chitinase activity of T. flavus. On the other hand, production of antifungal compounds and glucose-oxidase activity may play a role in antagonism of V. dahliae by retardation of germination and hyphal growth and melanization of newly formed microsclerotia.

An acidic class III chitinase in sugar beet: induction by Cercospora beticola, characterization, and expression in transgenic tobacco plants.

Abstract: An acidic chitinase (SE) was found to accumulate in leaves of sugar beet (Beta vulgaris) during infection with Cercospora beticola. Two isoforms, SE1 and SE2, with MW of 29 kDa and pI of approximately 3.0 were purified to homogeneity. SE2 is an endochitinase that also exhibits exochitinase activity, i.e., it is capable of hydrolyzing chito-oligosaccharides, including chitobiose, into N-acetyl-glucosamine. Partial amino acid sequence data for SE2 were used to obtain a cDNA clone by polymerase chain reaction. The clone was used to isolate a cDNA clone encoding SE2. The deduced amino acid sequence for SE2 is 58-67% identical to the class III chitinases from cucumber, Arabidopsis, and tobacco. A transient induction of SE2 mRNA during the early stages of infection with C. beticola is much stronger in tolerant plants than in susceptible plants. Transgenic tobacco (Nicotiana benthamiana) plants constitutively accumulate SE2 protein in the intercellular space of their leaves. In a preliminary infection experiment, the transgenic plants did not show increase in resistance against C. nicotianae.