RESUMO
In a bioprospecting study of paramo soils cultivated with potato (Solanum tuberosum), 50 fungal isolates were obtained and evaluated for their nitrate reductase (NR) activity, given the role played by this enzyme in the biosynthesis of silver nanoparticles (AgNps). Five isolates strain with high NR activity belonging to Penicillium simplicissimum, Aspergillus niger, and Fusarium oxysporum species were selected, verifying the presence of the NR enzyme in their enzymatic extract. Later, these strains showed the ability to biosynthesize AgNps with distorted spherical shapes and sizes ranging from 15 to 45 nm. Subsequently, an antibiosis test was carried out by the agar diffusion method using glass fiber disks against the phytopathogenic agent Pectobacterium carotovorum, finding halos of inhibition of bacterial growth up to 15.3 mm using a 100 ppm solution of the AgNps obtained from F. oxysporum. These results contribute to generating the basis of a new alternative for the control of this phytopathogenic agent of potato, challenging to manage by traditional methods and of relevance at the post-harvest level.
Assuntos
Fusarium , Nanopartículas Metálicas , Solanum tuberosum , Antibacterianos/farmacologia , Aspergillus niger , Pectobacterium carotovorum , Prata/farmacologia , Solanum tuberosum/microbiologiaRESUMO
Pectobacterium carotovorum is a phytopathogenic bacteria that causes significant economic loses in food crops, such as bell pepper, which is of special significance in the value of production and trade in Mexico. Therefore, a solution for fruit conservation must be sought. Due to environmental concerns, it is necessary the use of environmentally-friendly active packaging. In this article, chitosan and chitosan-thyme essential oil nanocoatings were used for the preservation of green bell pepper. Different formulations based on chitosan nanoparticles (CSNPs) and chitosan-thyme essential oil nanoparticles (15, 30, and 45%) were prepared. For uncoated and coated bell peppers, the quality and physiological variables of inoculated and uninoculated fruit with P. carotovorum during 12-day storage period were assessed. According to the results, the weight loss of the fruit remained almost constant over the storage days for the different formulations. A decrease in fruit firmness and an increase in the respiration rate and ascorbic acid content until day 8 with a decrease at the end of the storage period were observed. Of all the evaluated nanocoatings, the fruit treated with the formulation containing 15% CSNPs showed the lowest colony-forming units and disease incidence. Also, the coated bell peppers with this formulation had lower CO2 production compared to the remaining treatments, and the weight loss and firmness were maintained. Therefore, the use of CSNP coatings could represent a good alternative for the protection of bell pepper against the pathogenic bacteria P. carotovorum. PRACTICAL APPLICATION: The results of the application of nanocoatings based on chitosan and chitosan-thyme essential oil as an antibacterial agent against P. carotovorum on green bell pepper during 12-day storage period suggest that nanoparticle-based coatings can be a natural option for the preservation of fruit quality during ripening.
Assuntos
Capsicum , Embalagem de Alimentos/instrumentação , Armazenamento de Alimentos/métodos , Frutas/microbiologia , Nanopartículas , Óleos Voláteis , Ácido Ascórbico , Quitosana/química , México , Pectobacterium carotovorum/efeitos dos fármacos , Pectobacterium carotovorum/crescimento & desenvolvimento , Thymus (Planta)/químicaRESUMO
The Pectobacteriumcarotovorum species corresponds to a complex, including two subspecies with validly published names, two proposed subspecies and two new species, Pectobacterium polaris and Pectobacterium aquaticum. Recent studies suggested that this complex needed revision. We examined the taxonomic status of 144 Pectobacterium strains isolated from a wide range of plant species, various geographical origins and waterways. Sequences of the leuS, dnaX and recA housekeeping genes clustered 114 of these Pectobacterium strains together within a not yet described clade. We sequenced eight strains of this clade and analysed them together with the 102 Pectobacterium genomes available in the NCBI database. Phylogenetic analysis, average nucleotide identity calculation and in silico DNA-DNA hybridization allowed us to differentiate seven clades. This led us to propose the elevation of Pectobacterium carotovorumsubsp. odoriferum to species level as Pectobacteriumodoriferum sp. nov. (type strain CFBP 1878T=LMG 5863T=NCPPB 3839T=ICMP 11533T), the proposal of Pectobacteriumactinidiae sp. nov. (type strain KKH3=LMG 26003 T=KCTC 23131T) and Pectobacteriumbrasiliense sp. nov. (type strain CFBP 6617T= LMG 21371T=NCPPB 4609T), to emend the description of Pectobacterium carotovorum (type strain CFBP 2046T=LMG 2404T=NCPPB 312T=ICMP 5702T), and to propose a novel species, Pectobacterium versatile sp. nov (type strain CFBP6051T= NCPPB 3387T=ICMP 9168T) which includes the strains previously described as 'Candidatus Pectobacterium maceratum'. Phenotypic analysis performed using Biolog GENIII plates on eight strains of P. versatile sp. nov. and related strains completed our analysis.
Assuntos
Pectobacterium carotovorum/classificação , Pectobacterium/classificação , Filogenia , Plantas/microbiologia , Rios/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , França , Genes Bacterianos , Líbano , Marrocos , Hibridização de Ácido Nucleico , Pectobacterium/isolamento & purificação , Pectobacterium carotovorum/isolamento & purificação , Doenças das Plantas/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
BACKGROUND: Pectobacterium carotovorum subsp. brasiliense is a broad host range bacterial pathogen, which causes blackleg of potatoes and bacterial soft rot of vegetables worldwide. Production of plant cell wall degrading enzymes is usually critical for Pectobacterium infection. However, other virulence factors and the mechanisms of genetic adaptation still need to be studied in detail. RESULTS: In this study, the complete genome of P. carotovorum subsp. brasiliense strain SX309 isolated from cucumber was compared with eight other pathogenic bacteria belonging to the Pectobacterium genus, which were isolated from various host plants. Genome comparison revealed that most virulence genes are highly conserved in the Pectobacterium strains, especially for the key virulence determinants involved in the biosynthesis of extracellular enzymes and others including the type II and III secretion systems, quorum sensing system, flagellar and chemotactic genes. Nevertheless, some variable regions of the T6SS and the CRISP-Cas immune system are unique for P. carotovorum subsp. brasiliense. CONCLUSIONS: The extensive comparative genomics analysis revealed highly conserved virulence genes in the Pectobacterium strains. However, several variable regions of type VI secretion system and two subtype Cas mechanism-Cas immune systems possibly contribute to the process of Pectobacterium infection and adaptive immunity.
Assuntos
Genômica , Pectobacterium carotovorum/genética , Fenótipo , Imunidade Adaptativa/genética , Parede Celular/metabolismo , Quimiotaxia/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Flagelos/genética , Interações Hospedeiro-Patógeno , Lipopolissacarídeos/biossíntese , Pectobacterium carotovorum/citologia , Pectobacterium carotovorum/imunologia , Pectobacterium carotovorum/fisiologia , Análise de SequênciaRESUMO
Little information about the roles of circular RNAs (circRNAs) during potato-Pectobacterium carotovorum subsp. brasiliense (Pcb) interaction is currently available. In this study, we conducted the systematic identification of circRNAs from time series samples of potato cultivars Valor (susceptible) and BP1 (disease tolerant) infected by Pcb. A total of 2098 circRNAs were detected and about half (931, 44.38%) were intergenic circRNAs. And differential expression analysis detected 429 significantly regulated circRNAs. circRNAs play roles by regulating parental genes and sponging miRNAs. Gene Ontology (GO) enrichment of parental genes and miRNAs targeted mRNAs revealed that these differentially expressed (DE) circRNAs were involved in defense response (GO:0006952), cell wall (GO:0005199), ADP binding (GO:0043531), phosphorylation (GO:0016310), and kinase activity (GO:0016301), suggesting the roles of circRNAs in regulating potato immune response. Furthermore, weighted gene co-expression network analysis (WGCNA) found that circRNAs were closely related with coding-genes and long intergenic noncoding RNAs (lincRNAs). And together they were cultivar-specifically regulated to strengthen immune response of potato to Pcb infection, implying the roles of circRNAs in reprogramming disease responsive transcriptome. Our results will provide new insights into the potato-Pcb interaction and may lead to novel disease control strategy in the future.
Assuntos
Pectobacterium carotovorum/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , RNA de Plantas/genética , RNA/genética , Solanum tuberosum/genética , Solanum tuberosum/microbiologia , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , RNA Circular , TranscriptomaRESUMO
Abstract The draft genome of Pectobacterium carotovorum subsp. brasiliense (Pcb) which causes blackleg of potato was submitted to the NCBI and released with reference number NZ_LGRF00000000.1. The estimated genome size based on the draft genome assembly is 4,820,279 bp from 33 contigs ranging in length from 444 to 1,660,019 nucleotides. The genome annotation showed 4250 putative genes, 4114 CDS and 43 pseudo-genes. Three complete rRNA gene species were detected: nine 5S, one 16S and one 23S. Other partial rRNA gene fragments were also identified, nine 16S rRNA and three 23S rRNA. A total of 69 tRNA genes and one ncRNA gene were also annotated in this genome.
Assuntos
Genoma Bacteriano , Pectobacterium carotovorum/genética , Genômica , Análise de Sequência de DNA , Biologia Computacional/métodos , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência MolecularRESUMO
The draft genome of Pectobacterium carotovorum subsp. brasiliense (Pcb) which causes blackleg of potato was submitted to the NCBI and released with reference number NZ_LGRF00000000.1. The estimated genome size based on the draft genome assembly is 4,820,279 bp from 33 contigs ranging in length from 444 to 1,660,019 nucleotides. The genome annotation showed 4250 putative genes, 4114 CDS and 43 pseudo-genes. Three complete rRNA gene species were detected: nine 5S, one 16S and one 23S. Other partial rRNA gene fragments were also identified, nine 16S rRNA and three 23S rRNA. A total of 69 tRNA genes and one ncRNA gene were also annotated in this genome.(AU)
Assuntos
Pectobacterium carotovorum/genética , Sequenciamento Completo do Genoma , Solanum tuberosum/parasitologiaRESUMO
The draft genome of Pectobacterium carotovorum subsp. brasiliense (Pcb) which causes blackleg of potato was submitted to the NCBI and released with reference number NZ_LGRF00000000.1. The estimated genome size based on the draft genome assembly is 4,820,279bp from 33 contigs ranging in length from 444 to 1,660,019 nucleotides. The genome annotation showed 4250 putative genes, 4114 CDS and 43 pseudo-genes. Three complete rRNA gene species were detected: nine 5S, one 16S and one 23S. Other partial rRNA gene fragments were also identified, nine 16S rRNA and three 23S rRNA. A total of 69 tRNA genes and one ncRNA gene were also annotated in this genome.
Assuntos
Genoma Bacteriano , Genômica , Pectobacterium carotovorum/genética , Biologia Computacional/métodos , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Análise de Sequência de DNARESUMO
Plants have developed complex defense mechanisms to cope with microbial pathogens. Pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) are perceived by pattern recognition receptors (PRRs), leading to the activation of defense. While substantial progress has been made in understanding the activation of plant defense by PAMPs and DAMPs recognition in tracheophytes, far less information exists on related processes in early divergent plants like mosses. The aim of this study was to identify genes that were induced in P. patens in response to elicitors of Pectobacterium carotovorum subsp. carotovorum, using a cDNA suppression subtractive hybridization (SSH) method. A total of 239 unigenes were identified, including genes involved in defense responses related to the shikimate, phenylpropanoid, and oxylipin pathways. The expression levels of selected genes related to these pathways were analyzed using quantitative RT-PCR, confirming their rapid induction by P.c. carotovorum derived elicitors. In addition, P. patens induced cell wall reinforcement after elicitor treatment by incorporation of phenolic compounds, callose deposition, and elevated expression of Dirigent-like encoding genes. Small molecule defense markers and phytohormones such as cinnamic acid, 12-oxo-phytodienoic acid, and auxin levels all increased in elicitor-treated moss tissues. In contrast, salicylic acid levels decreased while abscisic acid levels remained unchanged. P. patens reporter lines harboring an auxin-inducible promoter fused to ß-glucuronidase revealed GUS activity in protonemal and gametophores tissues treated with elicitors of P.c. carotovorum, consistent with a localized activation of auxin signaling. These results indicate that P. patens activates the shikimate, phenylpropanoid, oxylipins, and auxin pathways upon treatment with P.c. carotovorum derived elicitors.
RESUMO
A ocorrência de Pectobacterium carotovorum subsp. carotovorum (=Erwinia carotovora subsp. carotovora) em cebolinha (Allium fistulosum) é relatada pela primeira vez na região norte do Brasil. Até então sua ocorrência estava registrada apenas no Distrito Federal.
This is the first report of Pectobacterium carotovorum subsp. carotovorum (=Erwinia carotovora subsp. carotovora) causing soft rot of bunching onion (Allium fistulosum) plants in Roraima, Brazil. Its occurrence is reported only in Distrito Federal.
Assuntos
Allium , Pectobacterium carotovorumRESUMO
This is the first report of Pectobacterium carotovorum subsp. carotovorum (=Erwinia carotovora subsp. carotovora) causing soft rot of bunching onion (Allium fistulosum) plants in Roraima, Brazil. Its occurrence is reported only in Distrito Federal.
A ocorrência de Pectobacterium carotovorum subsp. carotovorum (=Erwinia carotovora subsp. carotovora) em cebolinha (Allium fistulosum) é relatada pela primeira vez na região norte do Brasil. Até então sua ocorrência estava registrada apenas no Distrito Federal.