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1.
Int J Mol Sci ; 22(6)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803511

RESUMO

Rhizoctonia solani is the causer of black scurf disease on potatoes and is responsible for high economical losses in global agriculture. In order to increase the limited knowledge of the plants' molecular response to this pathogen, we inoculated potatoes with R. solani AG3-PT isolate Ben3 and carried out RNA sequencing with total RNA extracted from potato sprouts at three and eight days post inoculation (dpi). In this dual RNA-sequencing experiment, the necrotrophic lifestyle of R. solani AG3-PT during early phases of interaction with its host has already been characterised. Here the potato plants' comprehensive transcriptional response to inoculation with R. solani AG3 was evaluated for the first time based on significantly different expressed plant genes extracted with DESeq analysis. Overall, 1640 genes were differentially expressed, comparing control (-Rs) and with R. solani AG3-PT isolate Ben3 inoculated plants (+Rs). Genes involved in the production of anti-fungal proteins and secondary metabolites with antifungal properties were significantly up regulated upon inoculation with R. solani. Gene ontology (GO) terms involved in the regulation of hormone levels (i.e., ethylene (ET) and jasmonic acid (JA) at 3 dpi and salicylic acid (SA) and JA response pathways at 8 dpi) were significantly enriched. Contrastingly, the GO term "response to abiotic stimulus" was down regulated at both time points analysed. These results may support future breeding efforts toward the development of cultivars with higher resistance level to black scurf disease or the development of new control strategies.


Assuntos
Interações Hospedeiro-Patógeno/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Rhizoctonia/fisiologia , Solanum tuberosum/genética , Solanum tuberosum/microbiologia , Transcrição Genética , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genes de Plantas , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Doenças das Plantas/genética , Análise de Componente Principal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Solanum tuberosum/imunologia , Transcriptoma/genética , Regulação para Cima/genética
2.
Arch Virol ; 166(4): 1171-1175, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33559747

RESUMO

Seven novel tailed lytic viruses (Ds3CZ, Ds5CZ, Ds9CZ, Ds16CZ, Ds20CZ, Ds23CZ, Ds25CZ) infecting the bacterium Dickeya solani were isolated in the Czech Republic. Genomes of these viruses are dsDNA, 149,364 to 155,285 bp in length, and the genome arrangement is very similar to that of the type virus Dickeya virus LIMEstone 1. All but the Ds25CZ virus should be regarded as strains of a single species. Most of the sequence differences are due to the presence or absence of homing endonuclease (HE) genes, with 23 HEs found in Ds3CZ, Ds5CZ, and Ds20CZ, 22 in Ds9CZ, 19 in Ds16CZ, 18 in Ds25CZ, and 15 in Ds23CZ.


Assuntos
Caudovirales/genética , Caudovirales/isolamento & purificação , /virologia , Caudovirales/classificação , República Tcheca , DNA Viral/genética , Endonucleases/genética , Variação Genética , Genoma Viral/genética , Filogenia , Doenças das Plantas/microbiologia , Doenças das Plantas/virologia , Solanum tuberosum/microbiologia , Solanum tuberosum/virologia , Proteínas Virais/genética
3.
Methods Mol Biol ; 2232: 219-249, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33161551

RESUMO

The genus Streptomyces constitutes approximately 50% of all soil actinomycetes, playing a significant role in the soil microbial community through vital functions including nutrient cycling, production of bioactive metabolites, disease-suppression and plant growth promotion. Streptomyces produce many bioactive compounds and are prime targets for industrial and biotechnological applications. In addition to their agrobiological roles, some Streptomyces spp. can, however, be phytopathogenic, examples include, common scab of potato that causes economic losses worldwide. Currently used chemical control measures can have detrimental effect to environmental and human health as a result alternative methods to chemical disease control are being investigated. One alternative is the use of streptomycete specific phages to remove this pathogenic bacterium before it can cause the disease on potatoes. However, due to co-existence of non-common scab-causing species belonging to the genus Streptomyces, phage treatment is likely to affect a wide range of non-target streptomycete species including the beneficial ones in the soil. Therefore, before such treatment starts the host range of the phages within the targeted family of bacteria should be determined. In a study conducted using soil samples from a Tasmanian potato farm, streptomycetes were isolated and tested against streptomycete-specific phages. Their antifungal activity was also determined using multiple assays against selected phytopathogens. The four strongest antifungal activity-displaying isolates were further tested for their persistent antifungal activity using wheat and Fusarium solani in a pot trial. A second pot trial was also conducted to evaluate whether the beneficial streptomycetes were affected by streptophage treatment and whether their removal via the phage battery would cause opportunistic fungal infections to plants in soil. The streptomycetes prevented the reduction in wheat shoot weight caused by F. solani indicating their disease suppressive effect. However, when phages were added into the pots, the growth of wheat was detrimentally impacted. This finding might suggest that the reduced presence of antifungal streptomycetes via phage-induced lysis might encourage opportunistic fungal infections in plants.


Assuntos
Fusarium/patogenicidade , Solanum tuberosum/microbiologia , Streptomyces/química , Triticum/microbiologia , Actinomycetales/química , Actinomycetales/isolamento & purificação , Fazendas , Humanos , Doenças das Plantas/genética , Doenças das Plantas/prevenção & controle , Microbiologia do Solo , Solanum tuberosum/genética , Streptomyces/isolamento & purificação , Triticum/genética
4.
Int J Mol Sci ; 21(24)2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322721

RESUMO

Phytophthora is arguably one of the most damaging genera of plant pathogens. This pathogen is well suited to transmission via the international plant trade, and globalization has been promoting its spread since the 19th century. Early detection is essential for reducing its economic and ecological impact. Here, a shotgun proteomics approach was utilized for Phytophthora analysis. The collection of 37 Phytophthora isolates representing 12 different species was screened for species-specific peptide patterns. Next, Phytophthora proteins were detected in planta, employing model plants Solanum tuberosum and Hordeum vulgare. Although the evolutionarily conserved sequences represented more than 10% of the host proteome and limited the pathogen detection, the comparison between qPCR and protein data highlighted more than 300 protein markers, which correlated positively with the amount of P. infestans DNA. Finally, the analysis of P. palmivora response in barley revealed significant alterations in plant metabolism. These changes included enzymes of cell wall metabolism, ROS production, and proteins involved in trafficking. The observed root-specific attenuation in stress-response mechanisms, including the biosynthesis of jasmonates, ethylene and polyamines, and an accumulation of serotonin, provided the first insight into molecular mechanisms behind this particular biotic interaction.


Assuntos
Hordeum/microbiologia , Peptídeos/metabolismo , Phytophthora infestans/isolamento & purificação , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Solanum tuberosum/microbiologia , Cromatografia Líquida , Hordeum/enzimologia , Hordeum/metabolismo , Espectrometria de Massas , Redes e Vias Metabólicas , Phytophthora infestans/genética , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Reação em Cadeia da Polimerase , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Solanum tuberosum/metabolismo , Estresse Fisiológico
5.
Sensors (Basel) ; 20(24)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371462

RESUMO

The study evaluates the suitability of a field asymmetric ion mobility spectrometry (FAIMS) system for early detection of the Pythium leak disease in potato tubers simulating bulk storage conditions. Tubers of Ranger Russet (RR) and Russet Burbank (RB) cultivars were inoculated with Pythium ultimum, the causal agent of Pythium leak (with negative control samples as well) and placed in glass jars. The headspace in sampling jars was scanned using the FAIMS system at regular intervals (in days up to 14 and 31 days for the tubers stored at 25 °C and 4 °C, respectively) to acquire ion mobility current profiles representing the volatile organic compounds (VOCs). Principal component analysis plots revealed that VOCs ion peak profiles specific to Pythium ultimum were detected for the cultivars as early as one day after inoculation (DAI) at room temperature storage condition, while delayed detection was observed for tubers stored at 4 °C (RR: 5th DAI and RB: 10th DAI), possibly due to a slower disease progression at a lower temperature. There was also some overlap between control and inoculated samples at a lower temperature, which could be because of the limited volatile release. Additionally, data suggested that the RB cultivar might be less susceptible to Pythium ultimum under reduced temperature storage conditions. Disease symptom-specific critical compensation voltage (CV) and dispersion field (DF) from FAIMS responses were in the ranges of -0.58 to -2.97 V and 30-84% for the tubers stored at room temperature, and -0.31 to -2.97 V and 28-90% for reduced temperature, respectively. The ion current intensities at -1.31 V CV and 74% DF showed distinctive temporal progression associated with healthy control and infected tuber samples.


Assuntos
Espectrometria de Mobilidade Iônica , Doenças das Plantas/microbiologia , Tubérculos/microbiologia , Pythium/patogenicidade , Solanum tuberosum/microbiologia , Compostos Orgânicos Voláteis/análise , Biomarcadores/análise , Estudos de Viabilidade
6.
Nat Commun ; 11(1): 5802, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-33199718

RESUMO

A major bottleneck in identifying therapies to control citrus greening and other devastating plant diseases caused by fastidious pathogens is our inability to culture the pathogens in defined media or axenic cultures. As such, conventional approaches for antimicrobial evaluation (genetic or chemical) rely on time-consuming, low-throughput and inherently variable whole-plant assays. Here, we report that plant hairy roots support the growth of fastidious pathogens like Candidatus Liberibacter spp., the presumptive causal agents of citrus greening, potato zebra chip and tomato vein greening diseases. Importantly, we leverage the microbial hairy roots for rapid, reproducible efficacy screening of multiple therapies. We identify six antimicrobial peptides, two plant immune regulators and eight chemicals which inhibit Candidatus Liberibacter spp. in plant tissues. The antimicrobials, either singly or in combination, can be used as near- and long-term therapies to control citrus greening, potato zebra chip and tomato vein greening diseases.


Assuntos
Anti-Infecciosos/farmacologia , Ensaios de Triagem em Larga Escala , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Rhizobiaceae/fisiologia , Sequência de Bases , Citrus/efeitos dos fármacos , Citrus/microbiologia , Edição de Genes , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/microbiologia , Doenças das Plantas/microbiologia , Raízes de Plantas/genética , Rhizobiaceae/efeitos dos fármacos , Solanum tuberosum/efeitos dos fármacos , Solanum tuberosum/microbiologia , Transgenes
7.
PLoS One ; 15(9): e0239081, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925972

RESUMO

Sierra Mixe maize is a geographically remote landrace variety grown on nitrogen-deficient fields in Oaxaca, Mexico that meets its nutritional requirements without synthetic fertilizer by associating with free-living diazotrophs comprising the microbiota of its aerial root mucilage. We selected nearly 500 diazotrophic (N2-fixing) bacteria isolated from Sierra Mixe maize mucilage and sequenced their genomes. Comparative genomic analysis demonstrated that isolates represented diverse genera and composed three major diazotrophic groups based on nitrogen fixation gene content. In addition to nitrogen fixation, we examined deamination of 1-amino-1-cyclopropanecarboxylic acid, biosynthesis of indole-3-acetic acid, and phosphate solubilization as alternative mechanisms of direct plant growth promotion (PGP). Genome mining showed that isolates of all diazotrophic groups possessed marker genes for multiple mechanisms of direct plant growth promotion (PGP). Implementing in vitro assays corroborated isolate genotypes by measuring each isolate's potential to confer the targeted PGP traits and revealed phenotypic variation among isolates based on diazotrophic group assignment. Investigating the ability of mucilage diazotrophs to confer PGP by direct inoculation of clonally propagated potato plants in planta led to the identification of 16 bio-stimulant candidates. Conducting nitrogen-stress greenhouse experiments demonstrated that potato inoculation with a synthetic community of bio-stimulant candidates, as well as with its individual components, resulted in PGP phenotypes. We further demonstrated that one diazotrophic isolate conferred PGP to a conventional maize variety under nitrogen-stress in the greenhouse. These results indicate that, while many diazotrophic isolates from Sierra Mixe maize possessed genotypes and in vitro phenotypes for targeted PGP traits, a subset of these organisms promoted the growth of potato and conventional maize, potentially through the use of multiple promotion mechanisms.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Fixação de Nitrogênio , Zea mays/crescimento & desenvolvimento , Zea mays/microbiologia , Bactérias/genética , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Ácidos Indolacéticos/metabolismo , Fosfatos/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/microbiologia
8.
PLoS One ; 15(8): e0238148, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822425

RESUMO

Root treatment with oxathiapiprolin, benthiavalicarb or their mixture Zorvec-Endavia [ZE (3+7, w/w)] was shown to provide prolonged systemic protection against foliar oomycete pathogens attacking cucumber, tomato and basil. Here we report that these fungicides can effectively protect potato plants against late blight when applied to the soil in which such potato plants are grown. In two field experiments, performed in 2019 and 2020, potato plants grown in 64 L containers were treated with a soil drench of oxathiapiprolin, benthiavalicarb or ZE at 12.5, 25 or 50 mg ai/five plants in a container. Artificial inoculations with Phytophthora infestans revealed that such treated plants were protected against late blight in a dose-dependent manner all along the season. Interestingly, oxathiapiprolin persisted in the treated soil for at least 139 days, providing systemic protection against late blight to the following potato crops grown in that treated soils. Potato plants grown in loess soil in the field were either sprayed or drenched with ZE. Plants treated via the soil were significantly better protected against late blight compared to the plants treated by a spray. The data demonstrate a new strategy for season-long protection of potato against late blight by a single soil application of ZE. The systemic nature of oxathiapiprolin and benthiavalicarb composing ZE assures the translocation to the foliage of two fungicides with different modes of action. This shall minimize the risk of developing resistance against either fungicide in the treated crops.


Assuntos
Hidrocarbonetos Fluorados/administração & dosagem , Hidrocarbonetos Fluorados/farmacologia , Doenças das Plantas/prevenção & controle , Pirazóis/administração & dosagem , Pirazóis/farmacologia , Resistência à Doença/genética , Fungicidas Industriais/farmacologia , Phytophthora infestans/efeitos dos fármacos , Phytophthora infestans/patogenicidade , Raízes de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Solo , Solanum tuberosum/microbiologia
9.
PLoS One ; 15(8): e0236633, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785249

RESUMO

The induction of general plant defense responses following the perception of external elicitors is now regarded as the first level of the plant immune response. Depending on the involvement or not of these molecules in pathogenicity, this induction of defense is called either Pathogen-Associated Molecular Pattern (PAMP) Triggered Immunity or Pattern Triggered Immunity-both abbreviated to PTI. Because PTI is assumed to be a widespread and stable form of resistance to infection, understanding the mechanisms driving it becomes a major goal for the sustainable management of plant-pathogen interactions. However, the induction of PTI is complex. Our hypotheses are that (i) the recognition by the plant of PAMPs vs non-PAMP elicitors leads to specific defense profiles and (ii) the responses specifically induced by PAMPs target critical life history traits of the pathogen that produced them. We thus analyzed, using a metabolomic approach coupled with transcriptomic and hormonal analyses, the defense profiles induced in potato foliage treated with either a Concentrated Culture Filtrate (CCF) from Phytophthora infestans or two non-PAMP preparations, ß-aminobutyric acid (BABA) and an Ulva spp. Extract, used separately. Each elicitor induced specific defense profiles. CCF up-regulated sesquiterpenes but down-regulated sterols and phenols, notably α-chaconine, caffeoyl quinic acid and rutin, which decreased spore production of P. infestans in vitro. CCF thus induces both defense and counter-defense responses. By contrast, the Ulva extract triggered the synthesis of a large-spectrum of antimicrobial compounds through the phenylpropanoid/flavonoid pathways, while BABA targeted the primary metabolism. Hence, PTI can be regarded as a heterogeneous set of general and pathogen-specific responses triggered by the molecular signatures of each elicitor, rather than as a uniform, non-specific and broad-spectrum set of general defense reactions.


Assuntos
Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Imunidade Vegetal/imunologia , Solanum tuberosum/imunologia , Aminobutiratos/farmacologia , Resistência à Doença/efeitos dos fármacos , Flavonoides/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Fenóis/metabolismo , Phytophthora infestans/imunologia , Phytophthora infestans/patogenicidade , Doenças das Plantas/microbiologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Imunidade Vegetal/efeitos dos fármacos , Sesquiterpenos/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/microbiologia , Esteróis/metabolismo , Ulva/química
10.
PLoS One ; 15(7): e0235018, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673321

RESUMO

Common scab disease in potato has become a widespread issue in major potato production areas, leading to increasing economic losses. Varietal resistance is seen as a viable and long-term scab management strategy. However, the genes and mechanisms of varietal resistance are unknown. In the current study, a comparative RNA transcriptome sequencing and differential gene signaling and priming sensitization studies were conducted in two potato cultivars that differ by their response to common scab (Streptomyces scabies), for unraveling the genes and pathways potentially involved in resistance within this pathosystem. We report on a consistent and contrasted gene expression pattern from 1,064 annotated genes differentiating a resistant (Hindenburg) and a susceptible (Green Mountain) cultivars, and identified a set of 273 co-regulated differentially expressed genes in 34 pathways that more likely reflect the genetic differences of the cultivars and metabolic mechanisms involved in the scab pathogenesis and resistance. The data suggest that comparative transcriptomic phenotyping can be used to predict scab lesion phenotype in breeding lines using mature potato tuber. The study also showed that the resistant cultivar, Hindenburg, has developed and maintained a capacity to sense and prime itself for persistent response to scab disease over time, and suggests an immune priming reaction as a mechanism for induced-resistance in scab resistant potato cultivars. The set of genes identified, described, and discussed in the study paves the foundation for detailed characterizations towards tailoring and designing procedures for targeted gene knockout through gene editing and phenotypic evaluation.


Assuntos
Perfilação da Expressão Gênica , Solanum tuberosum/imunologia , Streptomyces/imunologia , Resistência à Doença/genética , Resistência à Doença/imunologia , Suscetibilidade a Doenças/imunologia , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/imunologia , Escabiose/microbiologia , Solanum tuberosum/microbiologia , Especificidade da Espécie , Streptomyces/patogenicidade
12.
Int J Syst Evol Microbiol ; 70(7): 4204-4211, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32553053

RESUMO

A novel bacterial strain, S40T, with strong antifungal activity was isolated from the rhizosphere of green potato collected from Zealand, Denmark. Polyphasic analysis with a combined phenotypic, phylogenetic and genomic approach was used to characterize S40T. Phylogenetic analysis based on the 16S rRNA gene and MLSA (concatenated gyrB, rpoD, infB and atpD sequences) showed that strain S40T was affiliated with the genus Serratia and with Serratia plymuthica PRI-2C as the closest related strain [average nucleotide identity (ANI), 99.26 %; DNA-DNA hybridization (dDDH), 99.20%]. However, whole genome sequence analyses revealed that S40T and S. plymuthica PRI-2C genomes displayed lower similarities when compared to all other S. plymuthica strains (ANI ≤94.34 %; dDDH ≤57.6 % relatedness). The DNA G+C content of strain S40T was determined to be 55.9 mol%. Cells of the strain were Gram-negative, rod-shaped, facultative anaerobic and displayed growth at 10-37 °C (optimum, 25-30 °C) and at pH 6-9 (optimum, pH 6-7). Major fatty acids were C16 : 0 (27.9 %), summed feature (C16 : 1 ω6c/C16 : 1 ω7c; 18.0 %) and C17 : 0 cyclo (15.1 %). The respiratory quinone was determined to be Q8 (94 %) and MK8 (95 %) and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The results of phenotypic, phylogenetic and genomic analyses support the hypothesis that strain S40T represents a novel species of the genus Serratia, for which the name Serratia inhibens sp. nov. is proposed. The type strain is S40T (=LMG 31467T=NCIMB 15235T). In addition, we propose that S. plymuthica PRI-2C is reclassified and transferred to the species S. inhibens as S. inhibens PRI-2C.


Assuntos
Antibiose , Filogenia , Serratia/classificação , Solanum tuberosum/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Dinamarca , Ácidos Graxos/química , Genes Bacterianos , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rizosfera , Análise de Sequência de DNA , Serratia/isolamento & purificação , Ubiquinona/química , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
PLoS One ; 15(4): e0231961, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32324785

RESUMO

Potato Alternaria leaf blight is one of the economically most important disease in potato production worldwide. A recent study reported a quick method to distinguish main Alternaria pathogens A. tenuissima, A. alternata, and A. solani using partial histone H3 gene sequences. Using this method, our collection of 79 isolates from 8 provinces in China were presumably separated into A. tenussima and A. alternata. But in depth morphological and genetic analysis casted doubt on this identification. Culture morphologies of six presumed A. alternata isolates (PresA_alt) and six presumed A. tenuissima isolates (PresA_ten) were not significantly different. PresA_ten isolates also produced conidia in branched chains which supposed to be A. aternata. Phylogenetic analyses were conducted using internal transcribed spacer region (ITS) and five genes commonly used for species identification including glyceraldehyde-3-phosphate dehydrogenase (GPDH), translation elongation factor 1-alpha (TEF1), ß-tubulin, plasma membrane ATPase (ATPase), and calmodulin genes. The results showed that GPDH and TEF1 sequences of PresA_alt and PresA_ten isolates were identical. The 12 isolates did not cluster by presumed species neither by individual or concatenated sequence comparisons. The phylogeny-trait association analysis confirmed that the two group isolates were undistinguishable by those molecular markers. Analysis of histone H3 gene sequences revealed variable intron sequences between PresA_ten and PresA_alt isolates, but the amino acid sequences were identical. Our results indicate that the previously published method to distinguish Alternaria species based on histone H3 gene sequence variation is inaccurate and that the prevalence of A. tenuissima isolates in China was likely overestimated.


Assuntos
Alternaria/genética , Alternaria/fisiologia , Histonas/genética , Solanum tuberosum/microbiologia , Alternaria/classificação , Marcadores Genéticos/genética , Filogenia , Doenças das Plantas/microbiologia , Especificidade da Espécie
14.
Mol Plant Microbe Interact ; 33(8): 1025-1028, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32310703

RESUMO

Phytophthora infestans is a devastating pathogen causing potato late blight (Solanum tuberosum). Here we report the sequencing, assembly and genome annotation for two Phytophthora infestans isolates sampled in Republic of Korea. Genome sequencing was carried out using long read (Oxford Nanopore) and short read (Illumina Nextseq) sequencing technologies that significantly improved the contiguity and quality of P. infestans genome assembly. Our resources would help researchers better understand the molecular mechanisms by which P. infestans causes late blight disease in the future.


Assuntos
Genoma , Phytophthora infestans , Doenças das Plantas/microbiologia , Solanum tuberosum/microbiologia , Anotação de Sequência Molecular , Phytophthora infestans/genética , Phytophthora infestans/patogenicidade
15.
Proc Natl Acad Sci U S A ; 117(17): 9613-9620, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32284406

RESUMO

In plants and animals, nucleotide-binding leucine-rich repeat (NLR) proteins are intracellular immune sensors that recognize and eliminate a wide range of invading pathogens. NLR-mediated immunity is known to be modulated by environmental factors. However, how pathogen recognition by NLRs is influenced by environmental factors such as light remains unclear. Here, we show that the agronomically important NLR Rpi-vnt1.1 requires light to confer disease resistance against races of the Irish potato famine pathogen Phytophthora infestans that secrete the effector protein AVRvnt1. The activation of Rpi-vnt1.1 requires a nuclear-encoded chloroplast protein, glycerate 3-kinase (GLYK), implicated in energy production. The pathogen effector AVRvnt1 binds the full-length chloroplast-targeted GLYK isoform leading to activation of Rpi-vnt1.1. In the dark, Rpi-vnt1.1-mediated resistance is compromised because plants produce a shorter GLYK-lacking the intact chloroplast transit peptide-that is not bound by AVRvnt1. The transition between full-length and shorter plant GLYK transcripts is controlled by a light-dependent alternative promoter selection mechanism. In plants that lack Rpi-vnt1.1, the presence of AVRvnt1 reduces GLYK accumulation in chloroplasts counteracting GLYK contribution to basal immunity. Our findings revealed that pathogen manipulation of chloroplast functions has resulted in a light-dependent immune response.


Assuntos
Cloroplastos/microbiologia , Regulação da Expressão Gênica de Plantas/imunologia , Luz , Proteínas NLR/metabolismo , Phytophthora infestans/metabolismo , Proteínas de Plantas/metabolismo , Agrobacterium/metabolismo , Animais , Cloroplastos/metabolismo , Escherichia coli/metabolismo , Proteínas Fúngicas , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Inativação Gênica , Microscopia Confocal , Proteínas NLR/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas de Plantas/genética , Plântula , Solanum tuberosum/metabolismo , Solanum tuberosum/microbiologia , Tabaco/metabolismo , Tabaco/microbiologia , Técnicas do Sistema de Duplo-Híbrido
16.
Mol Plant Microbe Interact ; 33(7): 872-875, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32240065

RESUMO

Ralstonia solanacearum, the causal agent of bacterial wilt and brown rot disease, is one of the major pathogens of solanaceous crops, including potato, around the globe. Biovar 2T (phylotype II/sequevar 25) of R. solanacearum is adapted to tropical lowlands and is only reported in South America and Iran. Thus far, no genome resource of the biovar 2T of the pathogen has been available. Here, we present the near-complete genome sequences of the biovar 2T strain CFBP 8697 as well as strain CFBP 8695 belonging to biovar 2 race 3, both isolated from potato in Iran. The genomic data of biovar 2T will extend our understanding of the virulence features of R. solanacearum and pave the way for research on biovar 2T functional and interaction genetics.


Assuntos
Genoma Bacteriano , Doenças das Plantas/microbiologia , Ralstonia solanacearum , Solanum tuberosum/microbiologia , Irã (Geográfico) , Filogenia , Ralstonia solanacearum/genética , Ralstonia solanacearum/patogenicidade
17.
PLoS One ; 15(4): e0230842, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240203

RESUMO

Globally, there is a high economic burden caused by pre- and post-harvest losses in vegetables, fruits and ornamentals due to soft rot diseases. At present, the control methods for these diseases are limited, but there is some promise in developing biological control products for use in Integrated Pest Management. This study sought to formulate a phage cocktail which would be effective against soft rot Pectobacteriaceae species affecting potato (Solanum tuberosum L.), with potential methods of application in agricultural systems, including vacuum-infiltration and soil drench, also tested. Six bacteriophages were isolated and characterized using transmission electron microscopy, and tested against a range of Pectobacterium species that cause soft rot/blackleg of potato. Isolated bacteriophages of the family Podoviridae and Myoviridae were able to control isolates of the Pectobacterium species: Pectobacterium atrosepticum and Pectobacterium carotovorum subsp. carotovorum. Genomic analysis of three Podoviridae phages did not indicate host genes transcripts or proteins encoding toxin or antibiotic resistance genes. These bacteriophages were formulated as a phage cocktail and further experiments showed high activity in vitro and in vivo to suppress Pectobacterium growth, potentially indicating their efficacy in formulation as a microbial pest control agent to use in planta.


Assuntos
Myoviridae/metabolismo , Pectobacterium/efeitos dos fármacos , Podoviridae/metabolismo , Bacteriófagos/genética , Agentes de Controle Biológico/metabolismo , Genômica , Myoviridae/genética , Pectobacterium/crescimento & desenvolvimento , Pectobacterium/metabolismo , Pectobacterium carotovorum/genética , Controle de Pragas/métodos , Filogenia , Doenças das Plantas/microbiologia , Podoviridae/genética , Solanum tuberosum/microbiologia
18.
Sci Rep ; 10(1): 4121, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139754

RESUMO

Given the major threat of phytopathogenic bacteria to food production and ecosystem stability worldwide, novel alternatives to conventional chemicals-based agricultural practices are needed to combat these bacteria. The objective of this study is to evaluate the ability of Pseudomonas segetis strain P6, which was isolated from the Salicornia europaea rhizosphere, to act as a potential biocontrol agent given its plant growth-promoting (PGP) and quorum quenching (QQ) activities. Seed biopriming and in vivo assays of tomato plants inoculated with strain P6 resulted in an increase in seedling height and weight. We detected QQ activity, involving enzymatic degradation of signal molecules in quorum sensing communication systems, against a broad range of N-acylhomoserine lactones (AHLs). HPLC-MRM data and phylogenetic analysis indicated that the QQ enzyme was an acylase. The QQ activity of strain P6 reduced soft rot symptoms caused by Dickeya solani, Pectobacterium atrosepticum and P. carotovorum on potato and carrot. In vivo assays showed that the PGP and QQ activities of strain P6 protect tomato plants against Pseudomonas syringae pv. tomato, indicating that strain P6 could have biotechnological applications. To our knowledge, this is the first report to show PGP and QQ activities in an indigenous Pseudomonas strain from Salicornia plants.


Assuntos
Chenopodiaceae/química , Pseudomonas/patogenicidade , Cromatografia Líquida de Alta Pressão , Daucus carota/microbiologia , Gammaproteobacteria/patogenicidade , Pectobacterium/patogenicidade , Pectobacterium carotovorum/patogenicidade , Pseudomonas syringae/patogenicidade , Percepção de Quorum/fisiologia , Solanum tuberosum/microbiologia
19.
J Plant Physiol ; 246-247: 153132, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32062292

RESUMO

Studies have shown that pathogenic bacteria infections induce the overproduction of reactive oxygen species (ROS) in plants. Cyanide-resistant respiration, an energy-dissipating pathway in plants, has also been induced by a pathogenic bacteria infection. However, it is unknown whether the induction of cyanide-resistant respiration under the pathogenic bacteria infection was caused by ROS. In this study, two pathogenic Erwinia strains were used to infect potato tuber, and membrane lipid peroxidation levels and the cyanide-resistant respiration capacity were determined. In addition, StAOX expression and regulation by ROS in potato tuber were analyzed. Moreover, the role of the Ca2+ pathway in regulating cyanide-resistant respiration was determined. The results showed that ROS induced cyanide-resistant respiration in potato tuber infected by Erwinia. Cyanide-resistant respiration inhibited the production of H2O2. Intracellular Ca2+ regulated the expression of calcium-dependent protein kinase (StCDPK1, StCDPK4, and StCDPK5) in potato, which indirectly controlled intracellular ROS levels. These results indicate that Ca2+ metabolism is involved in ROS-induced cyanide-resistant respiration.


Assuntos
Cianetos/metabolismo , Peroxidação de Lipídeos , Pectobacterium carotovorum/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Solanum tuberosum/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Tubérculos/enzimologia , Tubérculos/microbiologia , Tubérculos/fisiologia , Solanum tuberosum/enzimologia , Solanum tuberosum/microbiologia
20.
Can J Microbiol ; 66(7): 447-454, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32091915

RESUMO

The geocaulosphere is home to microbes that establish communication between themselves and others that disrupt them. These cell-to-cell communication systems are based on the synthesis and perception of signaling molecules, of which the best known belong to the N-acyl-homoserine lactone (AHL) family. Among indigenous bacteria, certain Gram-positive actinobacteria can sense AHLs produced by soft-rot Gram-negative phytopathogens and can degrade the quorum-sensing AHL signals to impair the expression of virulence factors. We mimicked this interaction by introducing dual-color reporter strains suitable for monitoring both the location of the cells and their quorum-sensing and -quenching activities, in potato tubers. The exchange of AHL signals within the pathogen's cell quorum was clearly detected by the presence of bright green fluorescence instead of blue in a portion of Pectobacterium-tagged cells. This phenomenon in Rhodococcus cells was accompanied by a change from red fluorescence to orange, showing that the disappearance of signaling molecules is due to rhodococcal AHL degradation rather than the inhibition of AHL production. Rhodococci are victorious in this fight for the control of AHL-based communication, as their jamming activity is powerful enough to prevent the onset of disease symptoms.


Assuntos
Percepção de Quorum/fisiologia , Acil-Butirolactonas/metabolismo , Controle Biológico de Vetores , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Rhodococcus/genética , Rhodococcus/metabolismo , Rhodococcus/fisiologia , Solanum tuberosum/microbiologia , Fatores de Virulência/metabolismo
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