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501.
The root-galling index of tomatoes inoculated with Meloidogyne javanica was decreased 70% when collagen was used as a soil amendment (0.1% w/w) and 90% when the amendment was supplemented with the collagenolytic fungus Cunninghamella elegans. The root-galling index was reduced 80% when the fungus was homogenized in collagen culture medium and added to soil without collagen supplement. Culture filtrates of the fungus C. elegans, grown on collagen as a single source of carbon and nitrogen, immobilized M. javanica second-stage juveniles and inhibited egg hatch. Root galling was reduced when tomato plants were inoculated with filtrate-treated juveniles. Culture filtrates reduced the motility of Rotylenchulus reniformis and Xiphinema index, but they had less effect on Anguina tritici and almost no effect on Ditylenchus dipsaci. Cunninghamella elegans had collagenolytic, elastolytic, keratinolytic, and nonspecific proteolytic activities when grown on collagen media, but only chitinolytic activity when grown on chitin media. 相似文献
502.
503.
The 5‘-region of the chitinase gene cabch29,derived from Brassica oleracea var.capitata,has been sequenced and analyzed for cis-acting elements important in controlling gene expression in transgenic tobacco plants.Different 5‘-deletion fragments were linked to reporter gene β-glucuronidase (GUS) as translational fusions,and the expression of these chimeric genes was analyzed in vegetative organs and tissues.Sequences up to-651 showed some basal GUS activity with nearly equal levels in wounded and intact tissues.The addition of further upstream sequences(-651 to-1284) enhanced expression level,and the expression driven by this fragment was inducible by a factor of two to three-fold by wounding.Histochemical analysis of different tissue from transgenic plants that contain cabch29 promoter-gus fusion gene demonstrated woundinducible and tissue-specific cabch29 promoter activity in plants containing the 1308 base pair fragment.The location of GUS activity appears to be cell-specific,being highest in vascular cells and epidermal cells of stem,leaf and roots.Meanwhile,the temporal and spatial expression of cabch29-GUS fusion gene has been investigated.Among the different vegetative organs,a high level of GUS activity was observed in stem and a moderate one in roots;whereas,wounding stress led to a high level of GUS in stem and moderate one in leaf. 相似文献
504.
INTRODUCTIONPlantshavedevelopedseveralbi0chemicaldefensemechanismsinresp0nsetopath0gensandabioticstress.Fo1l0wingpathogenattack,plantsynthesizephenyl-propaniodpr0ductssuchaslignin,l0wm0l.wt.antimicrobia1comp0undsknownasphyt0alexins,andseveraldefense-relatedproteins.Amongthesepr0teinsare"pathogenesis-relatedproteins"includingthefungalcellwalldegradingenzymeschitinaseandP-1,3-glucanase[1].Endochitinasefromhigherplantscatalyzethehydr0lysis0fchitin,aP-1,4-linkedhomop0lymerofN-acetyl-D-glucos… 相似文献
505.
Yu-Ching Wen Chia-Yen Lin Kuo-Hao Ho Yung-Wei Lin Chi-Hao Hsiao Shian-Shiang Wang Lun-Ching Chang Shun-Fa Yang Ming-Hsien Chien 《Journal of cellular and molecular medicine》2023,27(24):4202-4214
Chitinase 3-like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in advanced stages of several cancer types, including prostate cancer (PCa). Impacts of genetic variants of CHI3L1 on PCa development have not yet been investigated. The most common well-studied genetic variations are single-nucleotide polymorphisms (SNPs). Therefore, the objective of this study was to explore associations of CHI3L1 SNPs with both the susceptibility to PCa and its clinicopathological development. Three promoter SNPs, rs6691378 (−1371, G>A), rs10399805 (−247, G>A) and rs4950928 (−131, C>G), and one non-synonymous SNP, rs880633 (+2950, T>C), were analysed using a TaqMan allelic discrimination assay for genotyping in a cohort of 701 PCa patients and 701 healthy controls. Results indicated that there were no significant associations of PCa susceptibility with these four CHI3L1 SNPs. However, among elderly PCa patients (aged >65 years), it was observed that polymorphic variants (GA + AA) of CHI3L1 rs6691378 and 10399805 were significantly linked to reduced risks of several clinicopathological characteristics, including a high Gleason grade, advanced pathologic T stage and tumour cell invasion. Moreover, analyses of The Cancer Genome Atlas database revealed that CHI3L1 expression levels were elevated in PCa tissues compared with normal tissues. Interestingly, higher CHI3L1 expression levels were found to be associated with longer progression-free survival rates in PCa patients. Our findings indicated that levels of CHI3L1 may influence the progression of PCa, and the rs6691378 and 10399805 SNP genetic variants of CHI3L1 are linked to the clinicopathological development of PCa within a Taiwanese population. 相似文献
506.
Ming-Bo Qu Shao-Peng Sun Yuan-Sheng Liu Xiao-Rui Deng Jun Yang Qing Yang 《Insect Science》2021,28(3):692-704
The insect group II chitinase (ChtII, also known as Cht10) is a unique chitinase with multiple catalytic and chitin-binding domains. It has been proven genetically to be an essential chitinase for molting. However, ChtII's role in chitin degradation during insect development remains poorly understood. Obtaining this knowledge is the key to fully understanding the chitin degradation system in insects. Here, we investigated the role of OfChtII during the molting of Ostrinia furnacalis, a model lepidopteran pest insect. OfChtII was expressed earlier than OfChtI (OfCht5) and OfChi-h, at both the gene and protein levels during larva–pupa molting as evidenced by quantitative polymerase chain reaction and western blot analyses. A truncated OfChtII, OfChtII-B4C1, was recombinantly expressed in Pichia pastoris cells and purified to homogeneity. The recombinant OfChtII-B4C1 loosened compacted chitin particles and produced holes in the cuticle surface as evidenced by scanning electron microscopy. It synergized with OfChtI and OfChi-h when hydrolyzing insoluble α-chitin. These findings suggested an important role for ChtII during insect molting and also provided a strategy for the coordinated degradation of cuticular chitin during insect molting by ChtII, ChtI and Chi-h. 相似文献
507.
High-performance liquid chromatography mass spectrometry (HPLC MS) was employed to assess the binding behaviors of various
substrates to Vibrio harveyi chitinase A. Quantitative analysis revealed that hexaNAG preferred subsites −2 to +2 over subsites −3 to +2 and pentaNAG
only required subsites −2 to +2, while subsites −4 to +2 were not used at all by both substrates. The results suggested that
binding of the chitooligosaccharides to the enzyme essentially occurred in compulsory fashion. The symmetrical binding mode
(−2 to +2) was favored presumably to allow the natural form of sugars to be utilized effectively. Crystalline α chitin was
initially hydrolyzed into a diverse ensemble of chitin oligomers, providing a clear sign of random attacks that took place
within chitin chains. However, the progressive degradation was shown to occur in greater extent at later time to complete
hydrolysis. The effect of the reducing-end residues were also investigated by means of HPLC MS. Substitutions of Trp275 to
Gly and Trp397 to Phe significantly shifted the anomer selectivity of the enzyme toward β substrates. The Trp275 mutation
modulated the kinetic property of the enzyme by decreasing the catalytic constant (k
cat) and the substrate specificity (k
cat/K
m) toward all substrates by five- to tenfold. In contrast, the Trp397 mutation weakened the binding strength at subsite (+2),
thereby speeding up the rate of the enzymatic cleavage toward soluble substrates but slowing down the rate of the progressive
degradation toward insoluble chitin. 相似文献
508.
The expression of a baculovirus-derived chitinase gene increased resistance of tobacco cultivars to brown spot (Alternaria alternata) 总被引:6,自引:0,他引:6
J SHI C J THOMAS L A KING C R HAWES R D POSSEE M L EDWARDS D PALLETT J I COOPER 《The Annals of applied biology》2000,136(1):1-8
The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) chitinase gene coding region was amplified using the polymerase chain reaction, inserted into a plasmid (pROK‐2) and replicated in Escherichia coli XL1–blue. The recombinant plasmid was mobilised into Agrobacterium tumefaciens LBA 4404 and inoculated into tobacco leaf discs. The presence of the expressed chitinase in foliar tissue of kanamycin‐resistant plantlets of three Nicotiana tabacum cultivars (CF80, K326 and Xanthi‐nc) was inferred using immunoblotting, and enzyme activity was confirmed using a fluorometric assay. Confocal laser scanning microscopy with immunofluorescent staining of foliar sections from N. tabacum Xanthi‐nc expressing the viral chitinase indicated that the enzyme was restricted to the vascular tissue. Heliothis virescens larvae fed on leaf tissue expressing chitinase were not impaired either in their development to pupation or in their feeding behaviour, in comparision with their counterparts that had consumed similar amounts of untransformed tobacco leaf tissue. By contrast, when tobacco leaves were mechanically inoculated with Alternaria alternata, very few brown spots were observed at inoculation sites in chitinase‐expressing tissue, whereas large and spreading lesions formed in untransformed tobacco tissue. Of all lines that were transformed, as determined by kanamycin resistance, 59% had fewer symptoms of disease (smaller disease indices) than those for untransformed controls. 相似文献
509.
Hironobu Tsuchida Masahiko Kōmoto Hiromichi Kato Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(5):1143-1148
The nondialyzable melanoidin prepared from glucose-ammonia system (kept in pH 5.3~6.0 during the reaction) was hydrolyzed. The hydrolyzate was fractionated by DEAE-cellulose column and Dowex 50 W column. Deoxyfructosazine and its 6-isomer were respectively isolated from main two fractions, and identified. Even on boiling the melanoidin in aqueous solution, these pyrazines as well as imidazoles and β-hydroxy pyridines in the melanoidin were liberated.Furthermore, amounts of these heterocyclic compounds liberated from the nondialyzable melanoidin and the fractionated melanoidins (fractionated into five fractions on DEAE-cellulose column according to the method described previously) were examined.The results obtained seem to suggest that these heterocyclic compounds are not present probably as a molecular skelton or an inclusion compound in the melanoidin, but as a small moiety of the melanoidin molecule with loose chemical bond. 相似文献
510.
Extracellular enzyme production in solid culture media was analyzed in order to determine the variability among different Metarhizium anisopliae isolates. Using specific substrates, amylase, lipase, chitinase, and protease production was tested in 11 isolates from different regions of Brazil. Enzyme production was determined by the formation of a halo around the colony, and the diameters of both halo and colony were measured. The enzymatic index was expressed by the colony diameter/halo diameter ratio. In general, the isolates from the same region had similar enzymatic indexes, although similar indexes were also found for isolates from geographically distinct regions. The different isolates were tentatively grouped according to index similarity. 相似文献