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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.


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Journal ArticleDOI
TL;DR: Northern blot hybridization showed that the expression of these genes is induced upon infection with Fusarium graminearum, the first report of the induction of class-IV and class-VII chitinases in cereals by a fungal pathogen.
Abstract: Chitinases and β-1,3-glucanases are important components of plant defense in response to attack by pathogens. To identify specific chitinases and β-1,3-glucanases, we constructed a cDNA library using mRNA from wheat spikelets inoculated with conidia of Fusarium graminearum. Two chitinase and two β-1,3-glucanase clones were isolated using a rice chitinase Ia gene and barley cDNA clones for chitinase II and β-1,3-glucanase as probes. Sequence analysis showed that the cDNA clone SM194 encodes an acidic isoform of class-VII chitinase, the cDNA clone SM383 encodes a class-IV chitinase and the cDNA clones SM289 and SM638 encode two different acidic isoforms of β-1,3-glucanases. Nulli-tetrasomic analysis indicated that SM194 and SM383 were located on all of the group-2 chromosomes of wheat. Genetic mapping showed that at least three copies of class-IV and/or class-VII chitinase genes were clustered on the long arm of chromosome 2D of Aegilops tauschii and that they mapped genetically close to the centromere. SM289 and SM638 were located on all of the group 3 chromosomes of wheat by nulli-tetrasomic analysis, and to the β-1,3-glucanase clusters in the 3BL and 3DL chromosome arms of wheat by genetic mapping. Northern blot hybridization showed that the expression of these genes is induced upon infection with Fusarium graminearum. The accumulation of transcripts for these PR-proteins was more rapid in the resistant variety Sumai 3 than in its susceptible mutant during the first 24 h. This is the first report of the induction of class-IV and class-VII chitinases in cereals by a fungal pathogen.

150 citations

Journal ArticleDOI
TL;DR: Hydrolytic degradation of the chitin polymer is essential for hyphal growth, branching, and septum formation in fungal systems as well as for the normal molting of arthropods.
Abstract: Various pesticides are being used to destabilize, perturb, or inhibit crucial biochemical and physiological targets related to metabolism, growth, development, nervous communication, or behavior in pestiferous organisms. Chitin is an eukaryotic extracellular aminosugar biopolymer, massively produced by most fungal systems and by invertebrates, notably arthropods. Being an integral supportive component in fungal cell wall, insect cuticle, and nematode egg shell, chitin has been considered as a selective target for pesticide action. Throughout the elaborate processes of chitin formation and deposition, only the polymerization events associated with the cell membrane compartment are so far available for chemical interference. Currently, the actinomycetes-derived nucleoside peptide fungicides such as the polyoxins and the insecticidal benzoylaryl ureas have reached commercial pesticide status. The polyoxins and other structurally-related antibiotics like nikkomycins are strong competitive inhibitors of the polymerizing enzyme chitin synthase. The exact biochemical lesion inflicted by the benzoylaryl ureas is still elusive, but a post-polymerization event, such as translocation of chitin chains across the cell membrane, is suggested. Hydrolytic degradation of the chitin polymer is essential for hyphal growth, branching, and septum formation in fungal systems as well as for the normal molting of arthropods. Recently, insect chitinase activity was strongly and specifically suppressed by allosamidin, an actimomycetes-derived metabolite. In part, the defense mechanism in plants against invasion of pathogens is associated with induced chitinases. Chitin, chitosan, and their oligomers are able to act as elicitors which induce enhanced levels of chitinases in various plants. Lectins which bind to N-acetyl-D-glucosamine strongly interfere with fungal and insect chitin synthases. Plant lectins with similar properties may be involved in plant-pathogen interaction inter alia by suppressing fungal invasion.

150 citations

Journal ArticleDOI
TL;DR: Four new CI-4 derivatives are presented in complex with chitinase B from Serratia marcescens, providing further insight into the mechanism of inhibition of chitInases by cyclic dipeptides as well as providing a new scaffold for chit inase inhibitor design.
Abstract: Family 18 chitinases play an essential role in a range of pathogens and pests. Several inhibitors are known, including the potent inhibitors argadin and allosamidin, and the structures of these in complex with chitinases have been elucidated. Recent structural analysis has revealed that CI-4 [cyclo-(L-Arg-D-Pro)] inhibits family 18 chitinases by mimicking the structure of the proposed reaction intermediate. Here we report the high-resolution structures of four new CI-4 derivatives, cyclo-(L-Arg-L-Pro), cyclo-(Gly-L-Pro), cyclo-(L-His-L-Pro), and cyclo-(L-Tyr-L-Pro), in complex with a family 18 chitinase. In addition, details of enzyme inhibition and in vivo activity against Saccharomyces cerevisiae are presented. The structures reveal that the common cyclo-(Gly-Pro) substructure is sufficient for binding, allowing modification of the side chain of the nonproline residue. This suggests that design of cyclic dipeptides with a view to increasing inhibition of family 18 chitinases should be possible through relatively accessible chemistry. The derivatives presented here in complex with chitinase B from Serratia marcescens provide further insight into the mechanism of inhibition of chitinases by cyclic dipeptides as well as providing a new scaffold for chitinase inhibitor design.

148 citations

Journal ArticleDOI
TL;DR: This work found that a mixture of the B. bassiana Pr1A homolog (CDEP1) and Bbchit1 degraded insect cuticle in vitro more efficiently than either CDEP1 or BbChit1 alone, a significant step towards the development of hypervirulent insect pathogens for effective pest control.

148 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023186
2022337
2021148
2020172
2019154
2018152