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.

The Effect of Pseudomonas fluorescens and Fusarium oxysporum f.sp. cubense on Induction of Defense Enzymes and Phenolics in Banana

Abstract: The effect of Pseudomonas fluorescens treatment and Fusarium oxysporum f. sp. cubense inoculation on induction of phenylalanine ammonia-lyase (PAL), peroxidase (POX), chitinase, β-1,3-glucanase and accumulation of phenolics in banana (Musa sp.) was studied. When banana roots were treated with P. fluorescens strain Pf10, a two-fold increase in phenolic content in leaf tissues was recorded 3 – 6 d after treatment. Challenge inoculation with F. oxysporum, the wilt pathogen, steeply increased the phenolic content in P. fluorescens-treated banana plants. Significant increase in POX activity was detected 6 – 9 d after P. fluorescens treatment. PAL, chitinase and β-1,3-glucanase activities increased significantly from 3 d after P. fluorescens treatment and reached the maximum 6 d after treatment. Challenge inoculation with F. oxysporum further increased the enzyme activities. These results suggest that the enhanced activities of defense enzymes and elevated content of phenolics may contribute to bioprotection of banana plants against F. oxysporum.

Chitin‐supplemented Foliar Application of Serratia marcescens GPS 5 Improves Control of Late Leaf Spot Disease of Groundnut by Activating Defence‐related Enzymes

Abstract: Chitinolytic Serratia marcescens GPS 5 and non-chitinolytic Pseudomonas aeruginosa GSE 18, with and without supplementation of chitin, were tested for their ability to activate defence-related enzymes in groundnut leaves. Thirty-day-old groundnut (cv. TMV 2) plants pretreated with GPS 5 and GSE 18 (with and without supplementation of 1% colloidal chitin) were challenge inoculated after 24 h with Phaeoisariopsis personata, the causal agent of late leaf spot (LLS) disease of groundnut. GPS 5 and GSE 18, applied as a prophylactic spray, reduced the lesion frequency by 23% and 67%, respectively, compared with control. Chitin supplementation had no effect on the control of LLS by GSE 18, unlike GPS 5, which upon chitin supplementation reduced the lesion frequency by 64%, compared with chitin alone. In a time course study the activities of chitinase, β-1,3- glucanase, peroxidase and phenylalanine ammonia lyase were determined for the different treatments. There was an enhanced activity of the four defence-related enzymes with all the bacterial treatments when compared with phosphate buffer and colloidal chitin-treated controls. In correlation to disease severity in bacterial treatments, chitin-supplemented GSE 18 was similar to GSE 18, whereas chitin-supplemented GPS 5 was much more effective than GPS 5, in activation of the defence-related enzymes. The high levels of enzyme activities following chitin-supplemented GPS 5 application continued up to the measured 13 days after pathogen inoculation

Two chitinase-like proteins abundantly accumulated in latex of mulberry show insecticidal activity

Abstract: Plant latex is the cytoplasm of highly specialized cells known as laticifers, and is thought to have a critical role in defense against herbivorous insects Proteins abundantly accumulated in latex might therefore be involved in the defense system We purified latex abundant protein a and b (LA-a and LA-b) from mulberry (Morus sp) and analyzed their properties LA-a and LA-b have molecular masses of approximately 50 and 46 kDa, respectively, and are abundant in the soluble fraction of latex Western blotting analysis suggested that they share sequence similarity with each other The sequences of LA-a and LA-b, as determined by Edman degradation, showed chitin-binding domains of plant chitinases at the N termini These proteins showed small but significant chitinase and chitosanase activities Lectin RCA120 indicated that, unlike common plant chitinases, LA-a and LA-b are glycosylated LA-a and LA-b showed insecticidal activities when fed to larvae of the model insect Drosophila melanogaster Our results suggest that the two LA proteins have a crucial role in defense against herbivorous insects, possibly by hydrolyzing their chitin