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1.
Food Chem ; 330: 127230, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32526651

RESUMO

Chitooligosaccharides are oligosaccharides with many biological activities that can be used in food production for sweeteners, preservatives and humectants, among other products. Chitin, a long-chain polymer of N-acetylglucosamine and a derivative of glucose, can be hydrolyzed by applying chitinase to break down glycosidic bonds to form chitooligosaccharides. Chitinases arising from heterologous gene expression are usually linked to a 6 × His-tag to facilitate easy purification. Heterologously expressed chitinase linked to a 6 × His-tag is a transgenic element, but enzyme activity tests cannot be used to distinguish transgenic elements from natural elements. In this study, we established a rapid and easy method to detect His-tag-containing chitinase using gold nanoparticles (AuNPs) and ssDNA aptamers. Using this method, His-tag-containing chitinase could be detected at concentrations as low as 0.136 nM within 5 min. Color changes of AuNPs showed a positive correlation with His-tag-containing chitinase concentrations.


Assuntos
Aptâmeros de Nucleotídeos/química , Quitinases/metabolismo , DNA de Cadeia Simples/química , Ouro/química , Nanopartículas Metálicas/química , Quitina/análogos & derivados , Quitina/metabolismo , Cor , Hidrólise , Fatores de Tempo
2.
World J Microbiol Biotechnol ; 36(6): 90, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32524202

RESUMO

A chitinolytic bacterium Chitinophaga sp. S167 producing extracellular chitinases was isolated from a soil sample in India. The extracellular chitinases produced by S167 were concentrated by ammonium sulphate precipitation (AS70) and seven bands corresponding to chitinases were observed by zymography. Optimum temperature and pH of AS70 were between 40 and 45 °C and pH 6.0 respectively with high stability at 20-40 °C and pH 5-7. AS70 inhibited the growth of Fusarium oxysporum, Alternaria alternata and Cladosporium sp. in vitro. The culture conditions for the high level production of extracellular chitinases were optimized resulting in 48-folds higher chitinase production. As the combination of chitinases could be more potent in biocontrol of plant diseases, it was checked if AS70 could control postharvest fungal infection caused by Fusarium oxysporum on tomatoes. AS70 treated tomatoes showed significant lower incidence of infection (11%) by F. oxysporum as compared with 100% in the control at 5 days post inoculation. Further, AS70 caused significant mortality in second stage juveniles of root knot nematode, Meloidogyne incognita, a major agriculture pest responsible for economic losses in agriculture. This study highlights the antifungal and nematicidal activity of chitinases produced by Chitinophaga sp. S167. To the best of our knowledge, this is the first report of the biocontrol potential of the chitinases produced by Chitinophaga sp.


Assuntos
Antifúngicos/farmacologia , Bacteroidetes/isolamento & purificação , Quitinases/farmacologia , Doenças das Plantas/prevenção & controle , Alternaria/efeitos dos fármacos , Sulfato de Amônio , Bacteroidetes/enzimologia , Precipitação Química , Quitinases/metabolismo , Cladosporium/efeitos dos fármacos , Estabilidade Enzimática , Fusarium/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Microbiologia do Solo , Temperatura
3.
PLoS Pathog ; 16(5): e1008342, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32365117

RESUMO

Chitinases are important enzymes that contribute to the generation of carbon and nitrogen from chitin, a long chain polymer of N-acetylglucosamine that is abundant in insects, fungi, invertebrates and fish. Although mammals do not produce chitin, chitinases have been identified in bacteria that are key virulence factors in severe respiratory, gastrointestinal and urinary diseases. However, it is unclear how these enzymes are able to carry out this dual function. Legionella pneumophila is the causative agent of Legionnaires' disease, an often-fatal pneumonia and its chitinase ChiA is essential for the survival of L. pneumophila in the lung. Here we report the first atomic resolution insight into the pathogenic mechanism of a bacterial chitinase. We derive an experimental model of intact ChiA and show how its N-terminal region targets ChiA to the bacterial surface after its secretion. We provide the first evidence that L. pneumophila can bind mucins on its surface, but this is not dependent on ChiA. This demonstrates that additional peripheral mucin binding proteins are also expressed in L. pneumophila. We also show that the ChiA C-terminal chitinase domain has novel Zn2+-dependent peptidase activity against mammalian mucin-like proteins, namely MUC5AC and the C1-esterase inhibitor, and that ChiA promotes bacterial penetration of mucin gels. Our findings suggest that ChiA can facilitate passage of L. pneumophila through the alveolar mucosa, can modulate the host complement system and that ChiA may be a promising target for vaccine development.


Assuntos
Quitinases/metabolismo , Legionella pneumophila/metabolismo , Acetilglucosamina/metabolismo , Proteínas de Bactérias/metabolismo , Quitina/metabolismo , Quitinases/fisiologia , Regulação Bacteriana da Expressão Gênica/genética , Doença dos Legionários/metabolismo , Metais , Mucina-1/metabolismo , Mucinas/metabolismo , Proteólise , Relação Estrutura-Atividade , Fatores de Virulência/metabolismo
4.
Food Chem ; 324: 126891, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32339790

RESUMO

We determined whether heat and chemical treatments could reduce the decay of kiwifruit caused by Botrytis cinerea during postharvest storage. Kiwifruits were treated with 5 g/L (w/v) potassium sorbate (PS), with a 48 °C hot water treatment (HT), and with a combined treatment (HT + PS). Mycelial growth of B. cinerea and the postharvest quality of 'XuXiang' kiwifruits were evaluated. HT + PS significantly inhibited mycelial growth, germ tube growth, and spore germination of B. cinerea. This treatment also reduced the incidence of gray mold in kiwifruit postharvest, and enhanced activities of defense-related enzymes in kiwifruit tissues. Compared with the control, all treatments resulted in lower malondialdehyde (MDA) contents and higher total phenolic contents in kiwifruits. HT + PS also increased the activities of chitinase and ß-1,3-glucanase and the transcript levels of their encoding genes. HT + PS can improve kiwifruit quality and reduce decay during postharvest storage.


Assuntos
Actinidia/microbiologia , Botrytis/efeitos dos fármacos , Ácido Sórbico/farmacologia , Actinidia/química , Actinidia/enzimologia , Botrytis/genética , Quitinases/genética , Quitinases/metabolismo , DNA Fúngico/metabolismo , Qualidade dos Alimentos , Frutas/química , Frutas/enzimologia , Frutas/microbiologia , Glucana 1,3-beta-Glucosidase/genética , Glucana 1,3-beta-Glucosidase/metabolismo , Temperatura Alta , Malondialdeído/metabolismo , Fenóis/metabolismo
5.
Food Chem ; 320: 126599, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32222656

RESUMO

Antifreeze proteins restrict the growth of ice crystals during recrystallization and therefore find application in the protection of food products from damage upon freezing. Hippophae rhamnoides (seabuckthorn) is a freeze tolerant Himalayan shrub exhibiting antifreeze properties. Here, ~39 kDa class IV chitinase (HrCHI4) was purified from seabuckthorn seeds using chitin-affinity chromatography that showed antifreeze property by ice recrystallization inhibition. The application of HrCHI4 in cryopreservation of green beans was analyzed to verify its antifreeze potential. HrCHI4 pretreatment reduced the drip loss and electrolytic leakage in frozen beans, revealing that it preserved the membrane integrity upon cryopreservation. The texture analysis and SEM further validated structural maintenance. The volatile component analysis using GC-MS was performed to evaluate the quality of frozen beans. HrCHI4 contributed positively towards the retention of volatile components after freeze-thaw. In conclusion, a class IV chitinase HrCHI4 was purified from seabuckthorn seeds and its cryoprotective function was reported.


Assuntos
Quitinases/química , Criopreservação/métodos , Conservação de Alimentos/métodos , Verduras , Proteínas Anticongelantes/química , Proteínas Anticongelantes/isolamento & purificação , Proteínas Anticongelantes/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Quitinases/isolamento & purificação , Quitinases/metabolismo , Crioprotetores , Hippophae/enzimologia , Phaseolus
6.
Can J Microbiol ; 66(4): 274-287, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31961710

RESUMO

Fungal chitinases play essential roles in chitin degradation, cell wall remodeling, chitin recycling, nutrition acquisition, autolysis, and virulence. In this study, 18 genes of the glycoside hydrolase 18 (GH18) family were identified in the Isaria cicadae genome. Seventeen of the genes belonged to chitinases and one was an endo-ß-N-acetylglucosaminidase (ENGase). According to phylogenetic analysis, the 17 chitinases were designated as subgroups A (7 chitinases), B (7), and C (3). The exon-intron organizations of these genes were analyzed. The conserved regions DxxDxDxE and S/AxGG and the domains CBM1, CBM18, and CBM50 were detected in I. cicadae chitinases and ENGase. The results of analysis of expression patterns showed that genes ICchiA1, ICchiA6, ICchiB1, and ICchiB4 had high transcript levels in the different growth conditions or developmental stages. Subgroup A chitinase genes had higher transcript levels than the genes of all other chitinases. Subgroup B chitinase genes (except ICchiB7) presented higher transcript levels in chitin medium compared with other conditions. ICchiC2 and ICchiC3 were mainly transcribed in autolysis medium and in blastospores, respectively. Moreover, ICchiB1 presented higher transcript levels than genes of other chitinases. This work provides an overview of the GH18 chitinases and ENGase in I. cicadae and provides a context for the chitinolytic potential, functions, and biological controls of these enzymes of entomopathogenic fungi.


Assuntos
Quitinases/genética , Proteínas Fúngicas/genética , Fungos/enzimologia , Genoma Fúngico , Animais , Quitina/metabolismo , Quitinases/metabolismo , Proteínas Fúngicas/metabolismo , Fungos/genética , Insetos/microbiologia , Família Multigênica , Filogenia
7.
BMC Plant Biol ; 20(1): 1, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31898482

RESUMO

BACKGROUND: Witches' broom disease (WBD) of cacao (Theobroma cacao L.), caused by Moniliophthora perniciosa, is the most important limiting factor for the cacao production in Brazil. Hence, the development of cacao genotypes with durable resistance is the key challenge for control the disease. Proteomic methods are often used to study the interactions between hosts and pathogens, therefore helping classical plant breeding projects on the development of resistant genotypes. The present study compared the proteomic alterations between two cacao genotypes standard for WBD resistance and susceptibility, in response to M. perniciosa infection at 72 h and 45 days post-inoculation; respectively the very early stages of the biotrophic and necrotrophic stages of the cacao x M. perniciosa interaction. RESULTS: A total of 554 proteins were identified, being 246 in the susceptible Catongo and 308 in the resistant TSH1188 genotypes. The identified proteins were involved mainly in metabolism, energy, defense and oxidative stress. The resistant genotype showed more expressed proteins with more variability associated with stress and defense, while the susceptible genotype exhibited more repressed proteins. Among these proteins, stand out pathogenesis related proteins (PRs), oxidative stress regulation related proteins, and trypsin inhibitors. Interaction networks were predicted, and a complex protein-protein interaction was observed. Some proteins showed a high number of interactions, suggesting that those proteins may function as cross-talkers between these biological functions. CONCLUSIONS: We present the first study reporting the proteomic alterations of resistant and susceptible genotypes in the T. cacao x M. perniciosa pathosystem. The important altered proteins identified in the present study are related to key biologic functions in resistance, such as oxidative stress, especially in the resistant genotype TSH1188, that showed a strong mechanism of detoxification. Also, the positive regulation of defense and stress proteins were more evident in this genotype. Proteins with significant roles against fungal plant pathogens, such as chitinases, trypsin inhibitors and PR 5 were also identified, and they may be good resistance markers. Finally, important biological functions, such as stress and defense, photosynthesis, oxidative stress and carbohydrate metabolism were differentially impacted with M. perniciosa infection in each genotype.


Assuntos
Agaricales/imunologia , Cacau/microbiologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas/imunologia , Doenças das Plantas , Agaricales/fisiologia , Biomarcadores , Brasil , Cacau/genética , Quitinases/genética , Quitinases/metabolismo , Perfilação da Expressão Gênica , Genótipo , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/imunologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Domínios Proteicos Ricos em Prolina/genética , Inibidores da Tripsina/metabolismo
8.
Int J Mol Sci ; 21(2)2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31947682

RESUMO

Nowadays, applying bio-organic fertilizer (e.g., chitosan, Ch) or integrating beneficial microorganisms (e.g., arbuscular mycorrhizal fungi, AMF) are among the successful strategies to promote plant growth. Here, the effect of two application modes of Ch (foliar spray or root treatment) and Ch-derived nanoparticles (NPs) on tomato plants colonized with the AMF Rhizophagus irregularis were analyzed, thereby focusing on plant biomass, flowering and mycorrhization. An increase of shoot biomass and flower number was observed in arbuscular mycorrhizal (AM) plants sprayed with Ch. The interaction with AMF, however, was reduced as shown by decreased mycorrhization rates and AM-specific gene expression. To get insights into Ch effect on mycorrhization, levels of sugars, jasmonates, abscisic acid, and the expression of two chitinase-encoding genes were determined in mycorrhizal roots. Ch had no effect on sugar and phytohormone levels, but the reduced mycorrhization was correlated with down- and upregulated expression of Chi3 and Chi9, respectively. In contrast, application of NPs to leaves and Ch applied to the soil did not show any effect, neither on mycorrhization rate nor on growth of mycorrhizal plants. Concluding, Ch application to leaves enhanced plant growth and flowering and reduced interaction with AMF, whereas root treatment did not affect these parameters.


Assuntos
Quitinases/genética , Quitinases/metabolismo , Quitosana , Fertilizantes , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Micorrizas , Quitosana/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Nanopartículas
9.
Insect Biochem Mol Biol ; 119: 103326, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31968227

RESUMO

The antifungal activity of insect chitinase has rarely been studied. Here, we show that chitinase ChtIV, which is specifically expressed in the midgut of Asian corn borer (Ostrinia furnacalis), has antifungal activity toward phytopathogenic fungi. ChtIV exhibited high stability and mycelial hydrolytic activity in the extreme midgut environment, which has a pH of 10 and is rich in proteases. Hyper-N-glycosylation and reduced electrostatic interactions ensure the stability of ChtIV in the midgut. The structural characteristics of ChtIV are similar to two plant antifungal chitinases but distinct from an insect chitinase for cuticular chitin degradation in both the substrate-binding cleft and auxiliary binding motif. Since the phytopathogenic fungi are those that frequently invade corn, ChtIV may play a role in insect immune system and become a potential pesticide target. The crystal structures of ChtIV and its complexes with penta-N-acetylchitopentaose (a substrate) and allosamidin (an inhibitor) were obtained, which may facilitate rational design of ChtIV inhibitors as agrichemicals.


Assuntos
Antifúngicos/química , Quitinases/metabolismo , Proteínas de Insetos/metabolismo , Mariposas/metabolismo , Animais , Quitinases/química , Microbioma Gastrointestinal/efeitos dos fármacos , Proteínas de Insetos/química , Larva/química , Larva/crescimento & desenvolvimento , Larva/metabolismo , Mariposas/química , Mariposas/crescimento & desenvolvimento
10.
Artigo em Inglês | MEDLINE | ID: mdl-31958681

RESUMO

The cupuassu tree (Theobroma grandiflorum) is a crop of great economic importance to Brazil, mainly for its pulp and seeds, which are used in food industry. However, cupuassu fruit production is threatened by witches' broom disease caused by the fungus Moniliophthora perniciosa. As elements of its defense mechanisms, the plant can produce and accumulate pathogenesis-related (PR) proteins such as chitinases and osmotins. Here, we identified three cupuassu PR proteins (TgPR3, TgPR5 and TgPR8) from cupuassu-M. perniciosa interaction RNA-seq data. TgPR3 and TgPR8 corresponded to chitinases, and TgPR5 to osmotin; they are phylogenetically related to cacao and to Arabidopsis PR sequences involved in biotic and abiotic stress. The TgPR proteins' tridimensional structure was obtained through homology modeling, and molecular docking with chitin and chitosan showed that the TgPR proteins can interact with both cell wall molecules and presented a higher affinity for chitosan. TgPR gene expression was analyzed by RT-qPCR on resistant and susceptible cupuassu genotypes infected by M. perniciosa at 8, 24, 48 and 72 h after infection (hai). The TgPR genes showed higher expression in resistant plants compared to the susceptible ones, mainly for TgPR5 at 8 and 24 hai, while the expression was lower in the susceptible cupuassu plants. To our knowledge, this is the first in silico and in vitro reports of cupuassu PR protein. The data suggested that TgPRs could be involved in recognizing mechanisms of the plant's innate immune system through chitin receptors. Our results also suggest a putative role of chitinase/chitosanase for the TgPR5/osmotin.


Assuntos
Agaricales , Cacau , Quitinases , Resistência à Doença , Agaricales/fisiologia , Brasil , Cacau/enzimologia , Cacau/microbiologia , Quitinases/química , Quitinases/metabolismo , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo
11.
J Med Chem ; 63(3): 987-1001, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-31928006

RESUMO

Chitinases not only play vital roles in the human innate immune system but are also essential for the development of pathogenic fungi and pests. Chitinase inhibitors are efficient tools to investigate the elusive role of human chitinases and to control pathogens and pests. Via hierarchical virtual screening, we have discovered a series of chitinase inhibitors with a novel scaffold that have high inhibitory activities and selectivities against human and insect chitinases. The most potent human chitotriosidase inhibitor, compound 40, exhibited a Ki of 49 nM, and the most potent inhibitor of the insect pest chitinase OfChi-h, compound 53, exhibited a Ki of 9 nM. The binding of these two most potent inhibitors was confirmed by X-ray crystallography. In a murine model of bleomycin-induced pulmonary fibrosis, compound 40 was found to suppress the chitotriosidase activity by 60%, leading to a significant increase in inflammatory cells and suggesting that chitotriosidase played a protective role.


Assuntos
Quitinases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Animais , Bleomicina/farmacologia , Quitinases/metabolismo , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Inflamação/metabolismo , Lepidópteros/enzimologia , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Molecular , Ligação Proteica , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/metabolismo , Piridinas/química , Piridinas/metabolismo , Pirimidinas/química , Pirimidinas/metabolismo , Serratia marcescens , Relação Estrutura-Atividade
12.
Artigo em Inglês | MEDLINE | ID: mdl-31751767

RESUMO

Millipedes represent a model for the study of organic matter transformation, animal-microbial interactions, and compartmentalisation of digestion. The activity of saccharidases (amylase, laminarinase, cellulase, xylanase, chitinase, maltase, cellobiase, and trehalase) and protease were measured in the midgut and hindgut contents and walls of the millipedes Archispirostreptus gigas and Epibolus pulchripes. Assays done at pH 4 and 7 confirmed activities of all enzymes except xylanase. Hydrolysing of starch and laminarin prevailed. The hindgut of E. pulchripes was shorter, less differentiated. Micro-apocrine secretion was observed only in the midgut of A. gigas. Merocrine secretion was present in midgut and hindgut of E. pulchripes, and in the pyloric valve and anterior hindgut of A. gigas. Alpha-polysaccharidases were mostly active in the midgut content and walls, with higher activity at pH 4. The low activity of amylase (A. gigas) and laminarinase (E. pulchripes) in midgut tissue may indicate their synthesis in salivary glands. Cellulases were found in midgut. Chitinases, found in midgut content and tissue (E. pulchripes) or concentrated in the midgut wall (A. gigas), were more active at an acidic pH. Polysaccharidases were low in hindguts. Protease shows midgut origin and alkaline activity extending to the hindgut in E. pulchripes, whereas in A. gigas it is of salivary gland origin and acid activity restricted to the midgut. Some disaccharidases, with more alkaline activity, showed less apparent midgut-hindgut differences. It may indicate an axial separating of the primary and secondary digestion along the intestinal pH gradient or the presence of enzymes of hindgut parasites.


Assuntos
Artrópodes/enzimologia , Quitinases/metabolismo , Animais , Artrópodes/classificação , Celulase/metabolismo , Quitinases/fisiologia , Trato Gastrointestinal/enzimologia , Concentração de Íons de Hidrogênio , Peptídeo Hidrolases/metabolismo , Polissacarídeos/metabolismo , Especificidade por Substrato
13.
Phytochemistry ; 170: 112221, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31790908

RESUMO

The ICChI is a 35-kDa, glycosylated protein isolated from the latex of the weed Ipomoea carnea. It displays chitinase and lysozyme activity, which could be important for the defense against pathogenic fungi, insects and bacteria. The ICChI enzyme was crystallized, and a diffraction data set was collected from a single crystal to 1.42 Å resolution. The crystals belong to the primitive tetragonal space group P43212, with unit-cell parameters a = b = 57.9, c = 172.0 Å, and α = ß = Î³ = 90°. The structure was elucidated by molecular replacement method using a mixed model of three homologous structures from the N-terminal sequence of ICChI. The refined model consists of 272 amino acid residues and has a Rfactor of 18.93% and Rfree of 22.42%. The protein consists of a single globular domain with a (α/ß)8 triosephosphate isomerase barrel fold. Three of the consensus sites for N-glycosylation viz., Asn45, Asn172, and Asn194 containing carbohydrate moieties N-Acetylglucosamine (NAG), mannose, fucose, and xylose. The putative catalytic residues are Asp125, Glu127, and Tyr184. The crystal structure may provide fundamental information of GH18 family chitinases.


Assuntos
Quitinases/metabolismo , Ipomoea/química , Muramidase/metabolismo , Compostos Fitoquímicos/metabolismo , Proteínas de Plantas/metabolismo , Polissacarídeos/metabolismo , Quitinases/química , Ipomoea/metabolismo , Modelos Moleculares , Muramidase/química , Compostos Fitoquímicos/química , Proteínas de Plantas/química , Polissacarídeos/química
14.
Microbiol Res ; 231: 126353, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707299

RESUMO

Cladosporium spp. is a cosmopolitan fungal genus. In the literature, it has been reported as a biological agent for controlling several plant diseases, but its mechanism of action has never been clarified. The present study aims to identify Cladosporium spp. based on the DNA phylogeny of nine isolates obtained from the phylloplane of rice and their potential antagonistic activity against the main fungal pathogens that affect rice crop. Nine isolates of Cladosporium spp. were identified based on DNA phylogeny, molecular and morphological characterization, and their antagonistic effects with the rice pathogens C. miyabeanus, M. oryzae, M. albescens and S. oryzae. Four isolates were selected to study lytic enzymes such as ß-1,3-glucanase, chitinase and protease, and only one isolate was selected for a conidial germination and appressoria formation assay. The nine isolates were identified as C. cladosporioides, C. tenuissimum and C. subuliforme. Four isolates, identified as C. cladosporioides, inhibited the mycelial growth of rice pathogens such as C1H (68.59%) of S. oryzae, C5 G (74.32%) of C. miyabeanus, C11 G (75.97%) of M. oryzae and C24 G (77.39%) of M. albescens. C24 G showed a high activity of lytic enzymes, was tested against C. miyabeanus and M. oryzae, and inhibited conidial germination and appressorium formation by more than 59.36%. The characterization of C. cladosporioides suggested this species as a potential bioagent for the management of several rice diseases, especially rice blast. This is the first time that a potential biological agent from the genus Cladosporium identified at the species level was isolated from the rice phylloplane, and some of its mechanisms of action were demonstrated, such as increasing lytic enzyme activity against rice pathogens.


Assuntos
Cladosporium , Folhas de Planta/microbiologia , Patologia Vegetal , Antibiose , Ascomicetos/crescimento & desenvolvimento , Agentes de Controle Biológico , Quitinases/metabolismo , Cladosporium/enzimologia , Cladosporium/genética , Cladosporium/isolamento & purificação , DNA Ribossômico , Fungos não Classificados/crescimento & desenvolvimento , Glicosídeo Hidrolases/metabolismo , Magnaporthe/crescimento & desenvolvimento , Micoses , Oryza/microbiologia , Peptídeo Hidrolases/metabolismo , Filogenia , Doenças das Plantas
15.
Food Chem ; 305: 125483, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610420

RESUMO

Kiwifruit (Actinidia deliciosa cv. Jinkui) were treated with 0.1 mmol/L methyl jasmonate (MeJA) to investigate the effects on disease resistance to soft rot caused by Botryosphaeria dothidea. The results showed that MeJA treatment significantly reduced the diameter of lesions after inoculation with B. dothidea. This treatment significantly enhanced the activities of related antioxidant protective enzymes, defence-related enzymes including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO), chitinase (CHI), ß-1,3 glucanase (GLU) and increased the accumulation of total phenolic content, while the degree of membrane lipid peroxidation was reduced. MeJA treatment effectively enhanced gene expression of AcPOD, AcSOD, AcCHI and AcGLU. The results from this research suggest that MeJA treatment is a promising and safe strategy for controlling postharvest rot soft of kiwifruit.


Assuntos
Acetatos/farmacologia , Actinidia/microbiologia , Ascomicetos/efeitos dos fármacos , Ciclopentanos/farmacologia , Resistência à Doença/efeitos dos fármacos , Oxilipinas/farmacologia , Actinidia/química , Actinidia/metabolismo , Ascomicetos/fisiologia , Quitinases/genética , Quitinases/metabolismo , Frutas/química , Frutas/metabolismo , Frutas/microbiologia , Expressão Gênica/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidase/genética , Peroxidase/metabolismo , Fenóis/análise , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
16.
J Chem Ecol ; 46(1): 76-83, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31845135

RESUMO

Multiple species of phytophagous insects may co-occur on a plant and while plants can defend themselves from insect herbivory, plant responses to damage by different species and feeding guilds of insects may be asymmetric. Plants can trigger specific responses to elicitors/effectors in insect secretions altering herbivore performance. Recently, maize chitinases present in fall armyworm (FAW, Spodoptera frugiperda) frass were shown to act as effectors suppressing caterpillar-induced defenses in maize while increasing caterpillar performance. We investigated the effect of frass chitinase-mediated suppression of herbivore defenses in maize on the performance and preference of a subsequent insect herbivore from a different feeding guild, corn leaf aphid (Rhopalosiphum maidis). Aphid performance was highest on plants with FAW damage without frass chitinases compared to damaged plants with frass chitinases or undamaged plants. Plant exposure to frass chitinases post FAW damage also altered the production of herbivore-induced volatile compounds compared to damaged, buffer-treated plants. However, aphid preference to damaged, frass chitinase-treated plants was not different from damaged, buffer-treated plants or undamaged plants. This study suggests that frass effector-mediated alteration of plant defenses affects insect herbivores asymmetrically; while it enhances the performance of caterpillars, it suppresses the performance of subsequent herbivores from a different feeding guild.


Assuntos
Afídeos/fisiologia , Herbivoria/fisiologia , Zea mays/química , Animais , Afídeos/crescimento & desenvolvimento , Quitinases/metabolismo , Quitinases/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Larva/fisiologia , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Spodoptera/fisiologia , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Zea mays/metabolismo
17.
Anticancer Res ; 39(12): 6939-6943, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31810965

RESUMO

BACKGROUND/AIM: In spite of early detection, appoximately 15% of the small renal cell carcinomas (RCC) will develop metastasis within 5 years follow-up. The aim of this study was to identify new biomarkers to estimate the postoperative relapse of the most common conventional RCC. PATIENTS AND METHODS: Tissue multi arrays of conventional RCC without metastasis at the time of operation from a cohort of 634 patients were analysed by immunohistochemistry for expression of the chitinase 3-like protein 2 (CHI3L2). Cancer specific survival of patients was estimated with Kaplan-Meier analysis, univariate and multivariate Cox regression models. RESULTS: Kaplan-Meier analysis estimated a shorter cancer-free survival for patients with CHI3L2 positive tumors. In multivariate analysis, the CHI3L2 positivity associated with a 3.5 times higher risk for tumor relapse (p<0.001). CONCLUSION: Expression of CHI3L2 in tumor cells of conventional RCC define a group of patients at high risk for postoperative progression.


Assuntos
Carcinoma de Células Renais/metabolismo , Quitinases/metabolismo , Neoplasias Renais/metabolismo , Macrófagos/metabolismo , Recidiva Local de Neoplasia/metabolismo , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/cirurgia , Quitinases/genética , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/genética , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/cirurgia , Nefrectomia , Prognóstico , Análise de Sobrevida , Análise Serial de Tecidos , Regulação para Cima
18.
Int J Mol Sci ; 20(24)2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31861147

RESUMO

The reduction of synthetic chemistry use in modern viticulture relies on either the biological control of microorganisms or the induction of pathogenesis-related proteins. In the present study, the effects of hydro-alcoholic plant extracts (PEs) (i.e., by-products of Vitis vinifera L., leaves of Olea europaea L. and Ailanthus altissima (Mill.) Swingle) were tested on purified enzymes activity involved in plant-pathogen interactions. The polyphenolic composition was assayed and analyzed to characterize the extract profiles. In addition, suspension cell cultures of grapevine were treated with PEs to study their modulation of chitinase activity. Application of grape marc's PE enhanced chitinase activity at 4 g L-1. Additionally, foliar treatment of grape marc's PE at two doses (4 g L-1 and 800 g L-1) on grapevine cuttings induced a concentration-dependent stimulation of chitinase activity. The obtained results showed that the application of bioactive compounds based on PEs, rich in phenolic compounds, was effective both at in vitro and ex/in vivo level. The overall effects of PEs on plant-pathogen interaction were further discussed by applying a multi-criteria decision analysis, showing that grape marc was the most effective extract.


Assuntos
Quitinases/metabolismo , Extratos Vegetais/análise , Proteínas de Plantas/metabolismo , Polifenóis/análise , Vitis/metabolismo , Ailanthus/química , Células Cultivadas , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Olea/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Polifenóis/farmacologia , Vitis/efeitos dos fármacos
19.
J Food Sci ; 84(12): 3418-3428, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31762032

RESUMO

In order to study the effect of volatile organic compounds (VOCs) produced by Bacillus subtilis CF-3 combined with heat treatment on Monilinia fructicola in peach and Colletotrichum gloeosporioides in litchi fruit, fruits were treated with B. subtilis CF-3 VOCs and hot air alone or in combination. The quality indexes of peach and litchi fruit after treatment and the changes in defense-related enzymes were measured. The results showed that the B. subtilis CF-3 VOCs combined with heat treatment could significantly reduce the rot index of peach and litchi fruit, and effectively maintain firmness and soluble solids content, as well as reduce weight loss of fruits. The combined treatment effectively enhanced the activity of peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT), and superoxide dismutase (SOD) than either treatment alone, and enhanced the resistance of fruit to pathogenic fungi by activating disease-resistant enzymes (phenylalanine ammonia-lyase [PAL], chitinase [CHI], ß-1, 3-glucanase [GLU]) activity. In this study, B. subtilis CF-3 VOCs combined with heat treatment maintained the quality and delayed the decline of peach and litchi fruit, providing a theoretical basis for future applications. PRACTICAL APPLICATION: The combination of B. subtilis CF-3 VOCs and heat treatment reduce the extent of M. fructicola and C. gloeosporioides. The combination maintain the quality of peach and litchi better. The combination obviously improve the activity of defense-related enzyme in fruit.


Assuntos
Ascomicetos/efeitos dos fármacos , Bacillus subtilis/química , Colletotrichum/efeitos dos fármacos , Conservação de Alimentos/métodos , Litchi/microbiologia , Doenças das Plantas/microbiologia , Prunus persica/microbiologia , Compostos Orgânicos Voláteis/farmacologia , Ascomicetos/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Catecol Oxidase/metabolismo , Quitinases/metabolismo , Colletotrichum/crescimento & desenvolvimento , Frutas/enzimologia , Frutas/microbiologia , Temperatura Alta , Litchi/enzimologia , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/metabolismo , Prunus persica/enzimologia , Compostos Orgânicos Voláteis/metabolismo
20.
Molecules ; 24(23)2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31779078

RESUMO

Disruption in chitin regulation by using chitin synthesis inhibitor (novaluron) was investigated to gain insights into the biological activity of chitinase in red palm weevils, an invasive pest of date palms in the Middle East. Impact of novaluron against ninth instar red palm weevil larvae was examined by dose-mortality response bioassays, nutritional indices, and expression patterns of chitinase genes characterized in this study. Laboratory bioassays revealed dose-dependent mortality response of ninth-instar red palm weevil larvae with LD50 of 14.77 ppm of novaluron. Dietary growth analysis performed using different doses of novaluron (30, 25, 20, 15, 10, and 5 ppm) exhibited very high reduction in their indexes such as Efficacy of Conversion of Digested Food (82.38%) and Efficacy of Conversion of Ingested Food (74.27%), compared with control treatment. Transcriptomic analysis of red palm weevil larvae characterized numerous genes involved in chitin degradation including chitinase, chitinase-3-like protein 2, chitinase domain-containing protein 1, Endochitinase-like, chitinase 3, and chitin binding peritrophin-a domain. However, quantitative expression patterns of these genes in response to novaluron-fed larvae revealed tissue-specific time-dependent expression patterns. We recorded overexpression of all genes from mid-gut tissues. Growth retarding, chitin remodeling and larvicidal potential suggest novaluron as a promising alternate for Rhynchophorus ferrugineus management.


Assuntos
Quitina/metabolismo , Compostos de Fenilureia/metabolismo , Gorgulhos/metabolismo , Animais , Bioensaio/métodos , Quitinases/metabolismo , Perfilação da Expressão Gênica/métodos , Larva/metabolismo , Transcriptoma/fisiologia
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