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1.
BMC Plant Biol ; 21(1): 382, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34412592

RESUMO

BACKGROUND: Cysteine-rich receptor-like kinases (CRKs) represent a large subfamily of receptor-like kinases and play vital roles in diverse physiological processes in regulating plant growth and development. RESULTS: CaCRK5 transcripts were induced in pepper upon the infection of Ralstonia solanacearum and treatment with salicylic acid. The fusions between CaCRK5 and green fluorescence protein were targeted to the plasma membrane. Suppression of CaCRK5 via virus-induced gene silencing (VIGS) made pepper plants significantly susceptible to R. solanacearum infection, which was accompanied with decreased expression of defense related genes CaPR1, CaSAR8.2, CaDEF1 and CaACO1. Overexpression of CaCRK5 increased resistance against R. solanacearum in Nicotiana benthamiana. Furthermore, electrophoretic mobility shift assay and chromatin immunoprecipitation coupled with quantitative real-time PCR analysis revealed that a homeodomain zipper I protein CaHDZ27 can active the expression of CaCRK5 through directly binding to its promoter. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) analyses suggested that CaCRK5 heterodimerized with the homologous member CaCRK6 on the plasma membrane. CONCLUSIONS: Our data revealed that CaCRK5 played a positive role in regulating immune responses against R. solanacearum infection in pepper.


Assuntos
Capsicum/genética , Capsicum/microbiologia , Cisteína/genética , Cisteína/metabolismo , Resistência à Doença/genética , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Ralstonia solanacearum/patogenicidade , Capsicum/fisiologia , China , Resistência à Doença/fisiologia , Regulação da Expressão Gênica de Plantas
2.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361746

RESUMO

New agricultural strategies aim to reduce the use of pesticides due to their damage to the environment and humans, and the caused resistance to pathogens. Therefore, alternative sources of antifungal compounds from plants are under investigation lately. Extracts from plants have a wide composition of chemical compounds which may complicate the development of pathogen resistance. Botrytis cinerea, causing grey mould, is an important horticultural and ornamental pathogen, responsible for the relevant yield and quality losses. B. cinerea isolated from a different plant host may differ in the sensitivity to antifungal substances from plants. Assessing the importance of research covering a wide range of pathogens for the rapid development of biopesticides, this study aims to determine the sensitivity of the B. cinerea isolate complex (10 strains) to plant extracts, describe morphological changes caused by the extract treatment, and detect differences between the sensitivity of different plant host isolates. The results showed the highest sensitivity of the B. cinerea isolates complex to cinnamon extract, and the lowest to laurel extract. In contrast, laurel extract caused the most changes of morphological attributes in the isolates. Five B. cinerea isolates from plant hosts of raspberry, cabbage, apple, bell pepper, and rose were grouped statistically according to their sensitivity to laurel extract. Meanwhile, the bell pepper isolate separated from the isolate complex based on its sensitivity to clove extract, and the strawberry and apple isolates based on their sensitivity to cinnamon extract.


Assuntos
Antifúngicos/farmacologia , Agentes de Controle Biológico/farmacologia , Botrytis/efeitos dos fármacos , Cinnamomum zeylanicum/química , Hifas/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Antifúngicos/isolamento & purificação , Agentes de Controle Biológico/isolamento & purificação , Botrytis/crescimento & desenvolvimento , Botrytis/isolamento & purificação , Brassica/microbiologia , Capsicum/microbiologia , Cinnamomum camphora/química , Fragaria/microbiologia , Humanos , Hifas/crescimento & desenvolvimento , Hifas/isolamento & purificação , Malus/microbiologia , Testes de Sensibilidade Microbiana , Doenças das Plantas/microbiologia , Extratos Vegetais/química , Syzygium/química , Vitis/microbiologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-34424837

RESUMO

Three phytopathogenic bacterial strains (Pc19-1T, Pc19-2 and Pc19-3) were isolated from seedlings displaying water-soaked, dark brown-to-black, necrotic lesions on pepper (Capsicum annuum) leaves in Georgia, USA. Upon isolation on King's medium B, light cream-coloured colonies were observed and a diffusible fluorescent pigment was visible under ultraviolet light. Analysis of their 16S rRNA gene sequences showed that they belonged to the genus Pseudomonas, with the highest similarity to Pseudomonas cichorii ATCC 10857T (99.7 %). The fatty acid analysis revealed that the majority of the fatty acids were summed feature 3 (C16  :  1 ω7c/C16  :  1 ω6c), C16  :  0 and summed feature 8 (C18  :  1 ω7c/C18  :  1 ω6c). Phylogenomic analyses based on whole genome sequences demonstrated that the pepper strains belonged to the Pseudomonas syringae complex with P. cichorii as their closest neighbour, and formed a separate monophyletic clade from other species. Between the pepper strains and P. cichorii, the average nucleotide identity values were 91.3 %. Furthermore, the digital DNA-DNA hybridization values of the pepper strains when compared to their closest relatives, including P. cichorii, were 45.2 % or less. In addition, biochemical and physiological features were examined in this study and the results indicate that the pepper strains represent a novel Pseudomonas species. Therefore, we propose a new species Pseudomonas capsici sp. nov., with Pc19-1T (=CFBP 8884T=LMG 32209T) as the type strain. The DNA G+C content of the strain Pc19-1T is 58.4 mol%.


Assuntos
Capsicum/microbiologia , Filogenia , Pseudomonas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Georgia , Hibridização de Ácido Nucleico , Folhas de Planta/microbiologia , Pseudomonas/classificação , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201359

RESUMO

Red pepper (Capsicum annuum, L.), is one of the most important spice plants in Korea. Overwintering pepper fruits are a reservoir of various microbial pepper diseases. Here, we conducted metagenomics (DNA sequencing) and metatranscriptomics (RNA sequencing) using samples collected from three different fields. We compared two different library types and three different analytical methods for the identification of microbiomes in overwintering pepper fruits. Our results demonstrated that DNA sequencing might be useful for the identification of bacteria and DNA viruses such as bacteriophages, while mRNA sequencing might be beneficial for the identification of fungi and RNA viruses. Among three analytical methods, KRAKEN2 with raw data reads (KRAKEN2_R) might be superior for the identification of microbial species to other analytical methods. However, some microbial species with a low number of reads were wrongly assigned at the species level by KRAKEN2_R. Moreover, we found that the databases for bacteria and viruses were better established as compared to the fungal database with limited genome data. In summary, we carefully suggest that different library types and analytical methods with proper databases should be applied for the purpose of microbiome study.


Assuntos
Bactérias/genética , Capsicum/genética , Vírus de DNA/genética , Frutas/crescimento & desenvolvimento , Metagenoma , Vírus de RNA/genética , Transcriptoma , Bactérias/classificação , Capsicum/microbiologia , Capsicum/virologia , Vírus de DNA/classificação , Frutas/microbiologia , Frutas/virologia , Vírus de RNA/classificação , Estações do Ano
5.
Sci Rep ; 11(1): 9445, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33941790

RESUMO

Bacterial spot, caused by a group of Xanthomonads (Xanthomonas spp.), is a devastating disease. It can adversely affect the Capsicum annum productivity. Scientists are working on the role of antioxidants to meet this challenge. However, research is lacking on the role of antioxidant enzymes and their isoforms in the non-compatible pathogen and host plant interaction and resistance mechanisms in capsicum varieties. The present study was conducted to ascertain the defensive role of antioxidant enzymes and their isoforms in chilli varieties Hybrid, Desi, Serrano, Padron, and Shehzadi against bacterial spot disease-induced Xanthomonas sp. The seedlings were inoculated with bacterial pathogen @ 107 CFU/mL, and samples were harvested after regular intervals of 24 h for 4 days followed by inoculation. Total plant proteins were extracted in phosphate buffer and quantified through Bradford assay. The crude protein extracts were analyzed through quantitative enzymatic assays in order to document activity levels of various antioxidant enzymes, including peroxidase (POD), Catalase (CAT), Ascorbate peroxidase (APX), and Superoxide dismutase (SOD). Moreover, the profiles appearance of these enzymes and their isoforms were determined using native polyacrylamide gel electrophoresis (PAGE) analysis. These enzymes exhibited maximum activity in Hybrid (HiR) cultivar followed by Desi (R), Serrano (S), Padron, and Shehzadi (HS). Both the number of isoforms and expression levels were higher in highly resistant cultivars compared to susceptible and highly susceptible cultivars. The induction of POD, CAT, and SOD occurs at the early stages of growth in resistant Capsicum cultivars. At the same time, APX seems to make the second line of antioxidant defense mechanisms. We found that modulating antioxidant enzymes and isoforms activity at the seedling stage was an important mechanism for mitigating plant growth inhibition in the resistant ones.


Assuntos
Antioxidantes/metabolismo , Capsicum/microbiologia , Estresse Oxidativo/fisiologia , Doenças das Plantas/microbiologia , Estresse Fisiológico/fisiologia , Ascorbato Peroxidases/metabolismo , Capsicum/crescimento & desenvolvimento , Catalase/metabolismo , Peróxido de Hidrogênio/análise , Peroxidase/metabolismo , Proteínas de Plantas/análise , Isoformas de Proteínas/metabolismo , Superóxido Dismutase/metabolismo , Xanthomonas/patogenicidade
6.
Biomed Res Int ; 2021: 6673010, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33816626

RESUMO

Powdery mildew (PM) is a common fungal disease infecting pepper plants worldwide. Molecular breeding of pepper cultivars with powdery mildew resistance is desirable for the economic improvement of pepper cultivation. In the present study, 188 F5 population derived from AR1 (PM resistant) and TF68 (PM sensitive) parents were subjected to high-throughput genotyping by sequencing (GBS) for the identification of single nucleotide polymorphism (SNP) markers. Further, the identified SNP markers were utilized for the construction of genetic linkage map and QTL analysis. Overall read mapping percentage of 87.29% was achieved in this study with the total length of mapped region ranging from 2,956,730 to 25,537,525 bp. A total of 41,111 polymorphic SNPs were identified, and a final of 1,841 SNPs were filtered for the construction of a linkage map. A total of 12 linkage groups were constructed corresponding to each chromosome with 1,308 SNP markers with the map length of 2506.8 cM. Further, two QTLs such as Pm-2.1 and Pm-5.1 were identified in chromosomes 2 and 5, respectively, for the PM resistance. Overall, the outcomes of the present endeavor can be utilized for the marker-assisted selection of pepper with powdery mildew-resistant trait.


Assuntos
Capsicum/genética , Mapeamento Cromossômico , Resistência à Doença/genética , Genótipo , Doenças das Plantas/genética , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Capsicum/microbiologia , Doenças das Plantas/microbiologia
7.
Microbiol Res ; 248: 126751, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33839507

RESUMO

In this study, the seed endosphere of a bacterial wilt tolerant chilli cv. Firingi Jolokia was explored in order to find effective agents for bacterial wilt disease biocontrol. A total of 32 endophytic bacteria were isolated from freshly collected seeds and six isolates were selected based on R. solanacearum inhibition assay. These isolates were identified as Bacillus subtilis (KJ-2), Bacillus velezensis (KJ-4), Leuconostoc mesenteroides (KP-1), Lactococcus lactis (LB-3), Bacillus amyloliquefaciens (WK-2), and Bacillus subtilis (WK-3) by 16S rRNA gene sequencing. In the in planta R. solanacearum inhibition assay carried out by seedling root bacterization method, Bacillus subtilis (KJ-2) exhibited highest biocontrol efficacy of 86.6 % on 7th day post R. solanacearum inoculation and a minimum biocontrol efficacy of 52.9 % was noted for Leuconostoc mesenteroides (KP-1). GC-HRMS analysis detected several known antimicrobial compounds in the extract of the culture supernatant of Bacillus subtilis (KJ-2); which may contribute to inhibition of R. solanacearum. In the growth promotion assay conducted using these isolates, only two of them namely Bacillus subtilis (KJ-2) and Bacillus amyloliquefaciens (WK-2) showed growth promotion in true leafed tomato plants. All the selected seed endophytic isolates were able to control bacterial wilt of tomato at the seedling stage and Bacillus subtilis (KJ-2) was found to be most effective in controlling the disease. The results of the present study highlighted that seed endosphere of bacterial wilt tolerant cultivar is a rich source of R. solanacearum antagonizing bacterial isolates.


Assuntos
Antibiose , Bacillus/fisiologia , Capsicum/microbiologia , Proteção de Cultivos/métodos , Endófitos/fisiologia , Lactococcus/fisiologia , Doenças das Plantas/prevenção & controle , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Lactococcus/classificação , Lactococcus/genética , Lactococcus/isolamento & purificação , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Doenças das Plantas/microbiologia , Ralstonia solanacearum/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Sementes/microbiologia
8.
PLoS One ; 16(3): e0240279, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33705404

RESUMO

Bacterial spot (BS), incited by Xanthomonas campestris pv. vesicatoria (Xcv), is one of the most serious diseases of pepper. For a comparative analysis of defense responses to Xcv infection, we performed a transcriptomic analysis of a susceptible cultivar, ECW, and a resistant cultivar, VI037601, using the HiSeqTM 2500 sequencing platform. Approximately 120.23 G clean bases were generated from 18 libraries. From the libraries generated, a total of 38,269 expressed genes containing 11,714 novel genes and 11,232 differentially expressed genes (DEGs) were identified. Functional enrichment analysis revealed that the most noticeable pathways were plant-pathogen interaction, MAPK signaling pathway-plant, plant hormone signal transduction and secondary metabolisms. 1,599 potentially defense-related genes linked to pattern recognition receptors (PRRs), mitogen-activated protein kinase (MAPK), calcium signaling, and transcription factors may regulate pepper resistance to Xcv. Moreover, after Xcv inoculation, 364 DEGs differentially expressed only in VI037601 and 852 genes in both ECW and VI037601. Many of those genes were classified as NBS-LRR genes, oxidoreductase gene, WRKY and NAC transcription factors, and they were mainly involved in metabolic process, response to stimulus and biological regulation pathways. Quantitative RT-PCR of sixteen selected DEGs further validated the RNA-seq differential gene expression analysis. Our results will provide a valuable resource for understanding the molecular mechanisms of pepper resistance to Xcv infection and improving pepper resistance cultivars against Xcv.


Assuntos
Capsicum/genética , Perfilação da Expressão Gênica , Doenças das Plantas/genética , Xanthomonas campestris/patogenicidade , Xanthomonas vesicatoria/patogenicidade , Capsicum/metabolismo , Capsicum/microbiologia , Regulação para Baixo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , RNA de Plantas/química , RNA de Plantas/metabolismo , Análise de Sequência de RNA , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima
9.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668965

RESUMO

Bacterial wilt (BW) disease from Ralstonia solanacearum is a serious disease and causes severe yield losses in chili peppers worldwide. Resistant cultivar breeding is the most effective in controlling BW. Thus, a simple and reliable evaluation method is required to assess disease severity and to investigate the inheritance of resistance for further breeding programs. Here, we developed a reliable leaf-to-whole plant spread bioassay for evaluating BW disease and then, using this, determined the inheritance of resistance to R. solanacearum in peppers. Capsicum annuum 'MC4' displayed a completely resistant response with fewer disease symptoms, a low level of bacterial cell growth, and significant up-regulations of defense genes in infected leaves compared to those in susceptible 'Subicho'. We also observed the spreading of wilt symptoms from the leaves to the whole susceptible plant, which denotes the normal BW wilt symptoms, similar to the drenching method. Through this, we optimized the evaluation method of the resistance to BW. Additionally, we performed genetic analysis for resistance inheritance. The parents, F1 and 90 F2 progenies, were evaluated, and the two major complementary genes involved in the BW resistance trait were confirmed. These could provide an accurate evaluation to improve resistant pepper breeding efficiency against BW.


Assuntos
Bioensaio/métodos , Capsicum/microbiologia , Resistência à Doença/genética , Padrões de Herança/genética , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Ralstonia solanacearum/fisiologia , Capsicum/genética , Segregação de Cromossomos/genética , Progressão da Doença , Fenótipo , Doenças das Plantas/genética
10.
J Sci Food Agric ; 101(14): 5861-5871, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33788973

RESUMO

BACKGROUND: Two Fusarium fungi, F. oxysporum and F. proliferatum, have been recognized as major pathogenic fungi that cause postharvest decay of chili fruits. Ozone and some toxic chemicals are used to control pathogenic infections, leading to longer storage lives of agricultural commodities. However, these chemicals may pose some risks to the applicators and the environment. Therefore, alternative, easy-to-use fumigants for effective control of Fusarium infections in harvested fresh chilies are needed. RESULTS: Two endophytic fungi, Trichoderma afroharzianum strain MFLUCC19-0090 and T. afroharzianum strain MFLUCC19-0091, were isolated from Schefflera leucantha leaves. Their volatile compounds were investigated for antifungal activities against F. oxysporum and F. proliferatum. In vitro results showed that the volatile compounds produced by each strain inhibited pathogen growth. Additionally, the Trichoderma-derived volatile compounds significantly reduced Fusarium-related disease severity and incidence percentages in the inoculated fresh chilies. Antifungal properties of the volatile compounds were found to be specific to the species of the tested pathogens (MFLUCC19-0090 greatly suppressed F. oxysporum and MFLUCC19-0091 greatly suppressed F. proliferatum). Seventy-three volatile compounds were detected from both strains. Among the major volatile compounds detected, phenyl ethyl alcohol was found to possess the strongest antifungal activity against both pathogens. CONCLUSION: These Trichoderma-derived volatile compounds may be used as alternative fumigants for controlling Fusarium rot in harvested fresh chilies. The successful use of volatile compounds as biofumigants can prevent significant market losses and, more importantly, may reduce the health hazards caused by Fusarium-associated mycotoxin exposures among consumers. © 2021 Society of Chemical Industry.


Assuntos
Antifúngicos/farmacologia , Capsicum/microbiologia , Fusarium/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Trichoderma/química , Compostos Orgânicos Voláteis/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Araliaceae/microbiologia , Benzoquinonas , Cicloexanonas , Endófitos/química , Endófitos/isolamento & purificação , Endófitos/metabolismo , Fusarium/fisiologia , Hypocreales/química , Hypocreales/isolamento & purificação , Hypocreales/metabolismo , Doenças das Plantas/microbiologia , Trichoderma/isolamento & purificação , Trichoderma/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo
11.
BMC Microbiol ; 21(1): 70, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33663386

RESUMO

BACKGROUND: Paenibacillus polymyxa SC2, a bacterium isolated from the rhizosphere soil of pepper (Capsicum annuum L.), promotes growth and biocontrol of pepper. However, the mechanisms of interaction between P. polymyxa SC2 and pepper have not yet been elucidated. This study aimed to investigate the interactional relationship of P. polymyxa SC2 and pepper using transcriptomics. RESULTS: P. polymyxa SC2 promotes growth of pepper stems and leaves in pot experiments in the greenhouse. Under interaction conditions, peppers stimulate the expression of genes related to quorum sensing, chemotaxis, and biofilm formation in P. polymyxa SC2. Peppers induced the expression of polymyxin and fusaricidin biosynthesis genes in P. polymyxa SC2, and these genes were up-regulated 2.93- to 6.13-fold and 2.77- to 7.88-fold, respectively. Under the stimulation of medium which has been used to culture pepper, the bacteriostatic diameter of P. polymyxa SC2 against Xanthomonas citri increased significantly. Concurrently, under the stimulation of P. polymyxa SC2, expression of transcription factor genes WRKY2 and WRKY40 in pepper was up-regulated 1.17-fold and 3.5-fold, respectively. CONCLUSIONS: Through the interaction with pepper, the ability of P. polymyxa SC2 to inhibit pathogens was enhanced. P. polymyxa SC2 also induces systemic resistance in pepper by stimulating expression of corresponding transcription regulators. Furthermore, pepper has effects on chemotaxis and biofilm formation of P. polymyxa SC2. This study provides a basis for studying interactional mechanisms of P. polymyxa SC2 and pepper.


Assuntos
Capsicum/genética , Capsicum/microbiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Paenibacillus polymyxa/fisiologia , Transcriptoma/genética , Genes de Plantas/genética , Rizosfera
12.
J Microbiol Biotechnol ; 31(7): 978-989, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-33782224

RESUMO

Allyl isothiocyanate (AITC), as a fumigant, plays an important role in soil control of nematodes, soilborne pathogens, and weeds, but its effects on soil microorganisms are unclear. In this study, the effects of AITC on microbial diversity and community composition of Capsicum annuum L. soil were investigated through Illumina high-throughput sequencing. The results showed that microbial diversity and community structure were significantly influenced by AITC. AITC reduced the diversity of soil bacteria, stimulated the diversity of the soil fungal community, and significantly changed the structure of fungal community. AITC decreased the relative abundance of dominant bacteria Planctomycetes, Acinetobacter, Pseudodeganella, and RB41, but increased that of Lysobacter, Sphingomonas, Pseudomonas, Luteimonas, Pseudoxanthomonas, and Bacillus at the genera level, while for fungi, Trichoderma, Neurospora, and Lasiodiplodia decreased significantly and Aspergillus, Cladosporium, Fusarium, Penicillium, and Saccharomyces were higher than the control. The correlation analysis suggested cellulase had a significant correlation with fungal operational taxonomic units and there was a significant correlation between cellulase and fungal diversity, while catalase, cellulose, sucrase, and urease were the major contributors in the shift of the community structure. Our results will provide useful information for the use of AITC in the assessment of environmental and ecological security.


Assuntos
Capsicum/crescimento & desenvolvimento , Isotiocianatos/farmacologia , Microbiota/efeitos dos fármacos , Praguicidas/farmacologia , Microbiologia do Solo , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Capsicum/microbiologia , Capsicum/parasitologia , Enzimas/análise , Enzimas/metabolismo , Fungos/classificação , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Isotiocianatos/análise , Praguicidas/análise , Solo/química
13.
Int J Biol Macromol ; 178: 253-262, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33636267

RESUMO

The present study demonstrated that chitin-based nanofibers (CNFs) trigger the chitinase genes (PGIP1 and CaChi2), while elevating salicylic acid that can protect plants against pathogens. Cross-talk between this genetic induction and salicylic-acid-mediated immune response was also observed, which may arm a plant against multiple pathovars. Crab and mushroom based CNFs were synthesized by electrospinning and ball milling techniques. Plants (mung bean, Vigna radiata) (pepper, Capsicum annuum) were pre-inoculated with CNFs and treated with the pathogens Scrolotium rolfsii for pepper and Macrophomina phaseolina for mung bean and shrimp-based CNFs were used as a control. Treated plants had elevated levels of chitinase genes in response to CNFs at inoculation concentrations <10 mg/mL both in soil and media, to protect them against the pathogenic fungal disease. After 24 h of exposure to the pathogens, qRT-PCR showed genes class II chitinase gene (CaChi2) and polygalacturonase inhibitor protein 1 (PGIP1) to be up-regulated in both root and shoot at 0.1 and 1 mg/mL of inoculation, respectively. The ball milled mushroom CNFs were sufficient to trigger the membrane based enzymes with less diameter (≥15 nm) to be most efficient versus others. In vitro analysis showed IC50 of ball milled mushroom CNFs to be most efficient in limiting the growth of fungal biomass. Further trigger-like effects were prominent in reducing pathogenic fungal spread in both species.


Assuntos
Ascomicetos/imunologia , Capsicum , Membrana Celular , Quitina , Nanofibras/química , Doenças das Plantas , Imunidade Vegetal/efeitos dos fármacos , Vigna , Capsicum/imunologia , Capsicum/microbiologia , Membrana Celular/imunologia , Membrana Celular/microbiologia , Quitina/química , Quitina/farmacologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Vigna/imunologia , Vigna/microbiologia
14.
Int J Biol Macromol ; 177: 135-148, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33610604

RESUMO

Polylactic acid (PLA)/nano-TiO2(TiO2 NPs)/Graphene oxide (GO) nano-fibrous films were prepared by ultrasonic assisted electrostatic spinning technology, and the effects of TiO2 NPs:GO mass ratio and ultrasonic power on film morphology and mechanical, thermal, barrier and antibacterial properties were investigated. The addition of TiO2 NPs and GO can significantly increase the tensile strength and elongation at the break of PLA nano-fibrous films, and improve the water barrier properties of the nano-fibrous films. The antibacterial experiment showed that the inhibition rates of the nano-fibrous films against Escherichia coli and Staphylococcus aureus after 24 h exposure to UV irradiation reached 94.4 ± 1.8% and 92.6 ± 1.7% At the same time, the fresh-keeping packaging experiment of green peppers at room temperature, through the determination of hardness, soluble solids, chlorophyll content to determine the degree of decay of green pepper, it showed that PLA/TiO2 NPs/GO nano-fibrous films can better maintain the sensory quality of green peppers, delay the rate of spoilage of green peppers, and prolong the preservation period of green peppers.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Capsicum/microbiologia , Grafite/química , Nanopartículas/química , Poliésteres/química , Titânio/química , Escherichia coli/efeitos dos fármacos , Conservação de Alimentos/métodos , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacos
15.
J Appl Microbiol ; 131(3): 1452-1463, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33570812

RESUMO

AIMS: Application of volatile organic compounds (VOCs) from Streptomyces salmonis PSRDC-09 (VOCs PSRDC-09) grown on sterile wheat seeds against chili anthracnose pathogen was investigated in vitro and in vivo. METHODS AND RESULTS: Among 10 isolates of Colletotrichum species tested, Colletotrichum gloeosporioides PSU-03 was selected as the most aggressive anthracnose pathogenic strain on chili fruit against VOCs produced by Streptomyces species. Among 11 isolates, the strain PSRDC-09 exhibited the highest antifungal activity and was identified as S. salmonis PSRDC-09. The antagonistic mechanism of the VOCs PSRDC-09 on morphological of C. gloeosporioides PSU-03, observed by scanning electron microscope (SEM), revealed the irregular distortions in the fungal hyphae. The effect of inoculum size and spore concentration of S. salmonis PSRDC-09 prepared as a wheat seed inoculum on the suppression of C. gloeosporioides PSU-03 was studied both in vitro and on chili fruit. The optimum inoculum size (45 g 0·31 l-1 ) and spore concentration (107 spores per ml) of the wheat seed culture of S. salmonis PSRDC-09 exhibited the complete suppression (100% inhibition) on C. gloeosporioides PSU-03. The optimum fumigation period of the VOCs PSRDC-09 (45 g 1·38 l-1 ) was found to be 24 h. Based on gas chromatography-mass spectrometry (GC-MS) analysis, 14 major VOCs (produced by the strain PSRDC-09) were detected and l-linalool was the main volatile component. CONCLUSIONS: The results indicated that the VOCs from S. salmonis PSRDC-09 could effectively control the chili anthracnose disease caused by C. gloeosporioides. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings suggest that S. salmonis PSRDC-09 may have the potential to become a promising biofumigant for biocontrol of chili anthracnose disease in the postharvest system.


Assuntos
Capsicum/microbiologia , Colletotrichum , Fungicidas Industriais/farmacologia , Streptomyces , Compostos Orgânicos Voláteis , Agentes de Controle Biológico , Colletotrichum/patogenicidade , Frutas/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Streptomyces/química , Compostos Orgânicos Voláteis/farmacologia
16.
Sci Rep ; 11(1): 3610, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574410

RESUMO

Chilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.


Assuntos
Capsicum/microbiologia , DNA Intergênico/genética , Fusarium/genética , Doenças das Plantas/genética , Código de Barras de DNA Taxonômico , Fusarium/patogenicidade , Variação Genética/genética , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia
17.
BMC Plant Biol ; 21(1): 62, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33494714

RESUMO

BACKGROUND: Mexico is considered the diversification center for chili species, but these crops are susceptible to infection by pathogens such as Colletotrichum spp., which causes anthracnose disease and postharvest decay in general. Studies have been carried out with isolated strains of Colletotrichum in Capsicum plants; however, under growing conditions, microorganisms generally interact with others, resulting in an increase or decrease of their ability to infect the roots of C. chinense seedlings and thus, cause disease. RESULTS: Morphological changes were evident 24 h after inoculation (hai) with the microbial consortium, which consisted primarily of C. ignotum. High levels of diacylglycerol pyrophosphate (DGPP) and phosphatidic acid (PA) were found around 6 hai. These metabolic changes could be correlated with high transcription levels of diacylglycerol-kinase (CchDGK1 and CchDG31) at 3, 6 and 12 hai and also to pathogen gene markers, such as CchPR1 and CchPR5. CONCLUSIONS: Our data constitute the first evidence for the phospholipids signalling events, specifically DGPP and PA participation in the phospholipase C/DGK (PI-PLC/DGK) pathway, in the response of Capsicum to the consortium, offering new insights on chilis' defense responses to damping-off diseases.


Assuntos
Capsicum/imunologia , Colletotrichum/fisiologia , Consórcios Microbianos/fisiologia , Fosfolipídeos/metabolismo , Doenças das Plantas/imunologia , Imunidade Vegetal , Transdução de Sinais , Capsicum/genética , Capsicum/microbiologia , Colletotrichum/isolamento & purificação , Diacilglicerol Quinase , Difosfatos/metabolismo , Glicerol/análogos & derivados , Glicerol/metabolismo , Interações Hospedeiro-Patógeno , Ácidos Fosfatídicos/metabolismo , Filogenia , Doenças das Plantas/microbiologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Raízes de Plantas/microbiologia , Plântula/genética , Plântula/imunologia , Plântula/microbiologia , Fosfolipases Tipo C/metabolismo
18.
BMC Plant Biol ; 21(1): 67, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514310

RESUMO

BACKGROUND: Most plant viruses rely on vectors for their transmission and spread. One of the outstanding biological questions concerning the vector-pathogen-symbiont multi-trophic interactions is the potential involvement of vector symbionts in the virus transmission process. Here, we used a multi-factorial system containing a non-persistent plant virus, cucumber mosaic virus (CMV), its primary vector, green peach aphid, Myzus persicae, and the obligate endosymbiont, Buchnera aphidicola to explore this uncharted territory. RESULTS: Based on our preliminary research, we hypothesized that aphid endosymbiont B. aphidicola can facilitate CMV transmission by modulating plant volatile profiles. Gene expression analyses demonstrated that CMV infection reduced B. aphidicola abundance in M. persicae, in which lower abundance of B. aphidicola was associated with a preference shift in aphids from infected to healthy plants. Volatile profile analyses confirmed that feeding by aphids with lower B. aphidicola titers reduced the production of attractants, while increased the emission of deterrents. As a result, M. persicae changed their feeding preference from infected to healthy plants. CONCLUSIONS: We conclude that CMV infection reduces the B. aphidicola abundance in M. persicae. When viruliferous aphids feed on host plants, dynamic changes in obligate symbionts lead to a shift in plant volatiles from attraction to avoidance, thereby switching insect vector's feeding preference from infected to healthy plants.


Assuntos
Afídeos/virologia , Buchnera/fisiologia , Capsicum/virologia , Cucumovirus/fisiologia , Doenças das Plantas/virologia , Simbiose , Animais , Afídeos/efeitos dos fármacos , Afídeos/microbiologia , Afídeos/fisiologia , Capsicum/microbiologia , Capsicum/parasitologia , Comportamento Alimentar , Interações Hospedeiro-Parasita , Insetos Vetores/fisiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Rifampina/farmacologia , Compostos Orgânicos Voláteis/metabolismo
19.
Mol Plant Pathol ; 22(1): 3-18, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33151622

RESUMO

CaWRKY40 was previously found to be transcriptionally up-regulated by Ralstonia solanacearum inoculation (RSI) or heat stress (HS), but the underlying mechanism remains unknown. Herein, we report that a double-W box-element (DWE) in the promoter of CaWRKY40 is critical for these responses. The upstream W box unit WI of this composite element is crucial for preferential binding by CaWRKY40 and responsiveness to RSI or HS. DWE-driven CaWRKY40 can be transcriptionally and nonspecifically regulated by itself and by CaWRKY58 and CaWRKY27. The DWE was also found in the promoters of CaWRKY40 orthologs, including AtWRKY40, VvWRKY40, GmWRKY40, CplWRKY40, SaWRKY40, SpWRKY40, NtWRKY40, and NaWRKY40. DWEAtWRKY40 was analogous to DWECaWRKY40 by responding to RSI or HS and AtWRKY40 expression. These data suggest that a conserved response of plants to pathogen infection or HS is probably mediated by binding of the DWE by WRKY40.


Assuntos
Capsicum/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/imunologia , Ralstonia solanacearum/fisiologia , Fatores de Transcrição/metabolismo , Capsicum/imunologia , Capsicum/microbiologia , Capsicum/fisiologia , Resposta ao Choque Térmico , Interações Hospedeiro-Patógeno , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética
20.
Mol Plant Microbe Interact ; 34(1): 122-126, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33006530

RESUMO

Colletotrichum species cause anthracnose disease on the economically important spice crop chili. A total of 24 Colletotrichum species are known to infect chili and cause anthracnose. C. scovillei belongs to the C. acutatum species complex, and it shows greater aggressiveness than other species, particularly in the case of inoculation onto the nonwounded fruits of chili plants. The current work introduces an initial Illumina-Nanopore hybrid draft genome for C. scovillei TJNH1 together with the related annotations. Knowledge of this genome sequence provides an important reference genome of C. scovillei and will help further understand the pathogenic mechanism of C. scovillei to plant.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Capsicum , Colletotrichum , Genoma Fúngico , Doenças das Plantas , Capsicum/microbiologia , Colletotrichum/genética , Frutas/microbiologia , Genoma Fúngico/genética , Doenças das Plantas/microbiologia
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