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1.
Braz J Biol ; 84: e259983, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35507963

RESUMO

This study aimed to identify by molecular analysis, morphology, chemistry and antioxidant extracts of filamentous fungi isolated from the digestive tract of Phylloicus sp, an aquatic insect that lives on leaf packages in tropical streams and participates together with fungi of the decomposition of plant substrates in aquatic habitats. Insect larvae of Phylloicus sp. were collected in streams in the state of Tocantins, Brazil. Fungi were isolated from the digestive tract of larvae after disinfection and dissection, then described and purified for identification purposes and testing for antioxidant activity. Molecular identity was performed of ITS1 and ITS4, TUB e TEF sequencing. Fungal extracts were produced in 70% ethanol solution and later lyophilized. For analysis of chemical groups of extracts, thin layer chromatography (TLC) was performed in two mobile phases and different developers. Morphology was performed by optical microscopy stained with Toluidine Blue and measurement performed using the ImageJ program. Antioxidant activity performed in TLC and by quantitative method for DPPH and hydrogen peroxide (H2O2) radicals. Four fungi were identified: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana and Fusarium pseudocircinatum. The TLC showed several spots with acetone/chloroform mobile phase and UV 254 nm developers and I2 vapor. Fungal extracts demonstrate antioxidant action to reduce the DPPH free radical and especially for H2O2 above 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% and 92.3% for F. pseudocircinatum. This study demonstrated that the molecular technique by PCR was satisfactory for identifying fungi, and extracts with numerous chemical groups and potent reducing agents. Thus future work, should be carried out evaluating these four species for industrial use.


Assuntos
Antioxidantes , Peróxido de Hidrogênio , Animais , Antioxidantes/farmacologia , Fungos , Trato Gastrointestinal , Insetos , Extratos Vegetais
2.
Helminthologia ; 57(1): 37-42, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32063738

RESUMO

Based on morphology, measurements of juveniles and female specimens and sequences of the D2/ D3 expansion 28S rDNA gene and ITS1 analysis by DNA barcode technique, a Xiphinema americanum group species associated with olive trees from state of Sao Paulo, Brazil was identifi ed as X. santos. This is the first report of X. santos in Southern Hemisphere and outside the European and African continents, thus extending its geographic range.

3.
Plant Cell Rep ; 37(8): 1113-1125, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29796947

RESUMO

KEY MESSAGE: Regulatory sequences from the citrus constitutive genes cyclophilin (CsCYP), glyceraldehyde-3-phosphate dehydrogenase C2 (CsGAPC2), and elongation factor 1-alpha (CsEF1) were isolated, fused to the uidA gene, and qualitatively and quantitatively evaluated in transgenic sweet orange plants. The 5' upstream region of a gene (the promoter) is the most important component for the initiation and regulation of gene transcription of both native genes and transgenes in plants. The isolation and characterization of gene regulatory sequences are essential to the development of intragenic or cisgenic genetic manipulation strategies, which imply the use of genetic material from the same species or from closely related species. We describe herein the isolation and evaluation of the promoter sequence from three constitutively expressed citrus genes: cyclophilin (CsCYP), glyceraldehyde-3-phosphate dehydrogenase C2 (CsGAPC2), and elongation factor 1-alpha (CsEF1). The functionality of the promoters was confirmed by a histochemical GUS assay in leaves, stems, and roots of stably transformed citrus plants expressing the promoter-uidA construct. Lower uidA mRNA levels were detected when the transgene was under the control of citrus promoters as compared to the expression under the control of the CaMV35S promoter. The association of the uidA gene with the citrus-derived promoters resulted in mRNA levels of up to 60-41.8% of the value obtained with the construct containing CaMV35S driving the uidA gene. Moreover, a lower inter-individual variability in transgene expression was observed amongst the different transgenic lines, where gene constructs containing citrus-derived promoters were used. In silico analysis of the citrus-derived promoter sequences revealed that their activity may be controlled by several putative cis-regulatory elements. These citrus promoters will expand the availability of regulatory sequences for driving gene expression in citrus gene-modification programs.


Assuntos
Citrus sinensis/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Citrus sinensis/genética , Ciclofilinas/genética , Ciclofilinas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas/genética , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/genética
4.
Plant Dis ; 102(8): 1588-1598, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30673423

RESUMO

Local chlorotic spots resembling early lesions characteristic of citrus leprosis (CL) were observed in leaves of two sweet orange (Citrus sinensis L.) trees in Teresina, State of Piauí, Brazil, in early 2017. However, despite the similarities, these spots were generally larger than those of a typical CL and showed rare or no necrosis symptoms. In symptomatic tissues, transmission electron microscopy revealed the presence of viroplasms in the nuclei of the infected parenchymal cells and rod-shaped particles with an average size of approximately 40 × 100 nm, resembling those typically observed during infection by dichorhaviruses. A bipartite genome of the putative novel virus, tentatively named citrus chlorotic spot virus (CiCSV) (RNA1 = 6,518 nucleotides [nt] and RNA2 = 5,987 nt), revealed the highest nucleotide sequence identity values with the dichorhaviruses coffee ringspot virus strain Lavras (73.8%), citrus leprosis virus N strain Ibi1 (58.6%), and orchid fleck virus strain So (56.9%). In addition to citrus, CiCSV was also found in local chlorotic lesions on leaves of the ornamental plant beach hibiscus (Talipariti tiliaceum (L.) Fryxell). Morphological characterization of mites recovered from the infected plants revealed at least two different types of Brevipalpus. One of them corresponds to Brevipalpus yothersi. The other is slightly different from B. yothersi mites but comprises traits that possibly place it as another species. A mix of the two mite types collected on beach hibiscus successfully transmitted CiCSV to arabidopsis plants but additional work is required to verify whether both types of flat mite may act as viral vectors. The current study reveals a newly described dichorhavirus associated with a citrus disease in the northeastern region of Brazil.


Assuntos
Citrus/virologia , Doenças das Plantas/virologia , Vírus de Plantas/fisiologia , Rhabdoviridae/fisiologia , Animais , Brasil , Hibiscus/virologia , Microscopia Eletrônica de Varredura , Ácaros/ultraestrutura , Ácaros/virologia , Filogenia , Folhas de Planta/virologia , Vírus de Plantas/classificação , Vírus de Plantas/genética , Rhabdoviridae/classificação , Rhabdoviridae/genética , Proteínas Virais/classificação , Proteínas Virais/genética
5.
Neotrop Entomol ; 46(5): 499-506, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28185208

RESUMO

The Camponotus Mayr genus of carpenter ants is one of the largest in species number and widely represented in the Neotropical Region. Most species are generalists and capable of exploiting diverse habitats including urban environments. Urban green areas can act as a repository of regional biodiversity, thus we investigated whether this is valid for the largest city in South America. We compared the richness of Camponotus spp. in two green areas in regions with distinct urbanization profiles and also with previous surveys made in smaller cities and in natural areas of the original Atlantic Forest. Besides the usual capture of worker specimens, we included capture of alates to improve the species richness sampling. Morphological identification of Camponotus spp. is challenging, even more when alates are included. To assist in specimen identification, we performed DNA sequencing of mitochondrial and nuclear markers. The richness observed in the less stressed urban area was higher than in the more stressed one. Camponotus spp. reported in natural areas are largely represented in the urban area. DNA sequencing for specimen identification is hampered by the lack of corresponding sequences in the GenBank, but it helped to associate workers and alates of the same species and indicated the existence of cryptic species in the genus. Capture of alates allowed detection of several species for which workers were not sampled; therefore, it is a valuable tool for surveying diversity of Camponotus or other ant taxa with arboreal or hypogeic habits.


Assuntos
Formigas/classificação , Formigas/genética , Variação Genética , Genética Populacional , Animais , Brasil , Cidades , Ecossistema , Análise de Sequência de DNA
6.
Genet Mol Res ; 13(4): 9390-402, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-25501150

RESUMO

The occurrence of Fusarium spp associated with pecan tree (Carya illinoinensis) diseases in Brazil has been observed in recent laboratory analyses in Rio Grande do Sul State. Thus, in this study, we i) obtained Fusarium isolates from plants with disease symptoms; ii) tested the pathogenicity of these Fusarium isolates to pecan; iii) characterized and grouped Fusarium isolates that were pathogenic to the pecan tree based on morphological characteristics; iv) identified Fusarium spp to the species complex level through TEF-1α sequencing; and v) compared the identification methods used in the study. Fifteen isolates collected from the inflorescences, roots, and seeds of symptomatic plants (leaf necrosis or root rot) were used for pathogenicity tests. Morphological characterization was conducted using only pathogenic isolates, for a total of 11 isolates, based on the mycelial growth rate, sporulation, colony pigmentation, and conidial length and width variables. Pathogenic isolates were grouped based on morphological characteristics, and molecular characterization was performed by sequencing TEF-1α genes. Pathogenic isolates belonging to the Fusarium chlamydosporum species complex, Fusarium graminearum species complex, Fusarium proliferatum, and Fusarium oxysporum were identified based on the TEF-1α region. Morphological characteristics were used to effectively differentiate isolates and group the isolates according to genetic similarity, particularly conidial width, which emerged as a key morphological descriptor in this study.


Assuntos
Carya/microbiologia , Fusarium/citologia , Fusarium/genética , Doenças das Plantas/microbiologia , Árvores/microbiologia , Brasil , Contagem de Colônia Microbiana , Fusarium/isolamento & purificação , Fusarium/patogenicidade , Filogenia , Esporos Fúngicos/crescimento & desenvolvimento
7.
Plant Dis ; 98(2): 285, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30708755

RESUMO

In November 2012, plants of Russell prairie gentian (Eustoma grandiflorum, Lisianthus russellianus) were collected from a commercial greenhouse in Atibaia, SP, Brazil, displaying necrotic spots on leaves and necrosis on stems, followed by generalized systemic necrosis. Disease symptom incidence was estimated at 10%. Preliminary electron microscopy observations of negatively stained leaf extracts prepared from those lesions revealed the presence of a large number of spherical tospovirus-like, approximately 100 nm in diameter. Samples of infected leaves were ground in 0.01 M phosphate buffer containing 0.5% sodium sulphide and mechanically inoculated in six plants of each species of Nicotiana glutinosa, N. tabacum cv. White Burley, N. megalosiphon, N. debneyii, Datura stramonium, Chenopodium amaranticolor, C. quinoa, and E. grandiflorum. All inoculated plants displayed local lesions 4 to 5 days after inoculation, while N. debneyii and D. stramonium showed systemic symptoms, typical of Tospovirus infection. In addition, E. grandiflorum reproduced the original symptoms. Total RNA was extracted from infected E. grandiflorum and D. stramonium, and reverse transcription (RT)-PCR was performed using universal primers BR60 and BR65 (2) targeting conserved regions of the nucleocapsid gene (N). The amplification products of approximately 450 bp were purified, cloned, and sequenced. The unknown virus was identified as Chrysanthemum stem necrosis virus (CSNV-Lis) based on host range and nucleotide sequence (Genbank Accession No. KC894721) and showed 99% identity with a CSNV chrysanthemum isolate from Japan (AB600872). Maximum likelihood phylogenetic analysis using nine homologous CSNV sequences available in GenBank classified CSNV-Lis into a monophyletic group formed by chrysanthemum isolates from Japan and China while a Japanese lisianthus isolate was separately clustered. CSNV is a member of the genus Tospovirus (Bunyaviridae) and was first reported on chrysanthemum in Brazil (1) and later in the Netherlands, Slovenia, United Kingdom, and Japan (3). Despite scattered recent reports of CSNV, the simultaneous production of chrysanthemum and lisianthus crops along the year by Brazilian farmers has contributed to the virus maintenance in the field. The high identity between Brazilian and Japanese isolates of CSNV suggest a possible reintroduction of the virus through exchange of vegetative propagating material. References: (1) L. M. L. Duarte et al. J. Phytopathol. 143:569, 1995. (2) M. Eiras et al. Fitopatol. Bras. 26:170, 2001. (3) K. Momonoi et al. J. Gen. Plant Pathol. 77:142, 2011.

8.
Plant Dis ; 97(11): 1517, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30708485

RESUMO

Zamioculcas zamiifolia (Lodd.) Engl. ("Zanzibar Gem," "ZZ plant") is the monotypic species of the genus belonging to the family Araceae. It is a stemless perennial plant native to Africa, from Kenya to South Africa, that produces succulent rhizomes at the base of its attractive dark green and glossy foliage. Symptoms of mosaic and foliar distortion were observed on a plant purchased at an ornamental plants shop in São Paulo state, Brazil. In order to identify the causal agent, transmission and serological tests, as well as electron microscopy (EM) observations, reverse transcription (RT)-PCR, and sequencing were carried out. EM observations revealed the presence of elongated, flexuous viral particles in foliar extracts and cytoplasmic lamellar aggregates of type II lamellar inclusions (Edwardson's classification), in thin sections. No symptoms were induced following mechanical inoculation on Chenopodium amaranticolor, C. murale, Gomphrena globosa, Nicotiana megalosiphon, N. debneyii, nor on the aroids Philodendron scandens, P. selloum, Dieffenbachia amoena, Colocasia esculenta, and Z. zamiifolia. Up to 2 months after inoculation, plants were still symptomless, and the virus was not detected by RT-PCR. The indirect ELISA tests were negative with antisera against Dasheen mosaic virus (gift from F. W. Zettler, University of Florida) and Turnip mosaic virus (gift from P. Roggero, IFA, Turin, Italy). RT-PCR performed on the original purchased ornamental plant with potyvirus-specific primers (CI-R = ACICCRTTYTCDATDATRTTIGTIGC and CI-F = GGIVVIGTIGGIWSIGGIAARTCIAC) targeting the cytoplasmic inclusion protein cistron of the potyvirus genome produced a fragment of approximately 650 bp (GenBank Accession No. KC990386). The sequence was similar to those of potyvirus species with nucleotide identity, determined by PAUP v.4.0b10 for Macintosh, ranging from 64% for Pokeweed mosaic virus (JQ609065) to 93% for Konjac mosaic virus KoMV-F (NC007913). KoMV has been detected in aroid species in Taiwan, India, Korea, Japan (1,2), Germany, and The Netherlands (3,4). This is the first report of a viral disease on Z. zamiifolia and of KoMV in the Americas. Such information along with the vegetative propagation of ZZ plants strongly suggests that KoMV is spread worldwide. References: (1) P. Manikonda et al. J. Phytopathol. 159:133, 2011. (2) M. Nishiguchi et al. Arch Virol. 151:1643, 2006. (3) D.-E. Lesemann and S. Winter. Acta Hort. 568:135, 2002. (4) K. Pham et al. Acta Hort. 568:143, 2002.

9.
Arq. Inst. Biol. (Online) ; 77(2): 359-362, abr.-jun. 2010. ilus
Artigo em Inglês | VETINDEX, LILACS | ID: biblio-1391138

RESUMO

Ants are found worldwide playing an important environmental role. Some species are considered as agricultural pests and potential risk to human life and public health acting as pathogens carriers. Ants as Paratrechina longicornis and Camponotus spp. have been found inside hospitals. The aim of this study was the research of mycobacteria in 138 samples of ants (137 Paratrechina longicornis and only one Camponotus spp.) which got into the laboratories of tuberculosis diagnosis. These ants were suspended in sterile saline solution and inoculated into Petragnani and Stonebrink media, incubated at 37° C until 90 days and the isolates were identified as environmental mycobacteria (1 Mycobacterium fortuitum peregrinum, 1 Mycobacterium smegmatis) and 1 Mycobacterium tuberculosis complex. These results showed that ants should also act as mechanical vectors of mycobacteria dissemination in risk environments, reinforcing their significance in public health.


As formigas têm uma distribuição mundial e representam importante papel no ecossistema. Algumas espécies são consideradas pragas para a agricultura e um risco potencial à vida humana e à saúde pública veiculando mecanicamente agentes patogênicos. Formigas como Paratrechina longicornis e Camponotus spp. têm sido encontradas em ambientes hospitalares. O foco do presente estudo foi a identificação de micobactérias em 138 amostras de formigas (137 Paratrechina longicornis e apenas uma Camponotus sp.), que tiveram acesso a áreas de laboratórios de diagnóstico de tuberculose. Essas formigas foram suspensas em solução salina estéril que foi semeada em meios de Petragnani e Stonebrink, incubadas a 37º C por até 90 dias e as estirpes de micobactérias isoladas foram identificadas pelas técnicas clássicas como micobactérias ambientais (sendo 1 Mycobacterium smegmatis, 2 Mycobacterium fortuitum peregrinum e 1 Mycobacterium tuberculosis). Esses resultados mostram que as formigas podem também se constituir vetores de dispersão de micobactérias em ambientes de risco, reforçando sua importância em saúde pública.


Assuntos
Formigas/microbiologia , Tuberculose/prevenção & controle , Doenças Transmitidas por Vetores/prevenção & controle , Mycobacterium/isolamento & purificação , Mycobacterium tuberculosis/isolamento & purificação , Vigilância em Saúde Pública
10.
Braz. j. microbiol ; 40(4): 952-959, Oct.-Dec. 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-528180

RESUMO

The objectives of the present study were the subtyping of Campylobacter jejuni subsp. jejuni strains obtained from humans and different animal species using PCR-RFLP, and the detection, by means of the same technique, of strains related to serotype PEN O19:LIO 7, the main C. jejuni serotype linked to Guillain-Barré Syndrome (GBS). Seventy C. jejuni strains isolated from human feces (n=33), primates (n=15), dogs (n=5), swine (n=2), bovines (n=1), abortion material from goats (n=2) and poultry carcasses (n=12), all collected in the state of São Paulo, were subtyped by means of PCR-RFLP of fla A gene, using restriction endonucleases Hae III, Afa I and Mbo I. Seven subtypes were observed when using the enzyme Hae III; eight when using Mbo I; and seven when using Afa I. The combination of the three endonucleases led to 16 fla-RFLP subtypes, from which ten subtypes shared strains of human and animal origin. From these, seven subtypes were observed in human and broiler strains. In eight subtypes, the other animal species shared patterns with human strains. It was inferred that, besides broilers, swine, goats, dogs and primates may be sources of infection for human in São Paulo. PCR-RFLP is a highly discriminatory technique that may be applied to molecular epidemiology studies of samples from different origins. Besides, the study also enabled the detection of two human strains and two primate strains related to serotype PEN O19: LIO 7.


Assuntos
Humanos , Animais , Infecções por Campylobacter , Campylobacter jejuni/isolamento & purificação , Técnicas e Procedimentos Diagnósticos , Técnicas In Vitro , Polimorfismo de Fragmento de Restrição , Reação em Cadeia da Polimerase/métodos , Síndrome de Guillain-Barré/diagnóstico , Estudos Epidemiológicos , Métodos , Estudos de Amostragem , Métodos
11.
Braz J Microbiol ; 40(4): 952-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24031446

RESUMO

The objectives of the present study were the subtyping of Campylobacter jejuni subsp. jejuni strains obtained from humans and different animal species using PCR-RFLP, and the detection, by means of the same technique, of strains related to serotype PEN O19:LIO 7, the main C. jejuni serotype linked to Guillain-Barré Syndrome (GBS). Seventy C. jejuni strains isolated from human feces (n=33), primates (n=15), dogs (n=5), swine (n=2), bovines (n=1), abortion material from goats (n=2) and poultry carcasses (n=12), all collected in the state of São Paulo, were subtyped by means of PCR-RFLP of fla A gene, using restriction endonucleases Hae III, Afa I and Mbo I. Seven subtypes were observed when using the enzyme Hae III; eight when using Mbo I; and seven when using Afa I. The combination of the three endonucleases led to 16 fla-RFLP subtypes, from which ten subtypes shared strains of human and animal origin. From these, seven subtypes were observed in human and broiler strains. In eight subtypes, the other animal species shared patterns with human strains. It was inferred that, besides broilers, swine, goats, dogs and primates may be sources of infection for human in São Paulo. PCR-RFLP is a highly discriminatory technique that may be applied to molecular epidemiology studies of samples from different origins. Besides, the study also enabled the detection of two human strains and two primate strains related to serotype PEN O19: LIO 7.

12.
Plant Dis ; 91(5): 525-531, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-30780696

RESUMO

Citrus black spot, caused by Guignardia citricarpa, is a serious fruit spot disease and is widely distributed in Asia, southern Africa, and South America, but does not occur in North America or the Mediterranean region. A nonpathogenic species, G. mangiferae, is cosmopolitan with a wide host range and can colonize citrus fruit and leaves saprophytically. Detection and identification of Guignardia spp. on citrus fruit is necessary for epidemiological, management, and regulatory purposes. In this study, we compared published and unpublished polymerase chain reaction primer sets for their specificity and sensitivity in the detection and differentiation of the two Guignardia spp. All primers evaluated successfully identified the two species using purified DNA from fungal cultures or mycelia as source materials. However, some primer sets were not highly effective in detecting G. citricarpa when DNA was extracted directly from single characteristic black spot lesions on fruit. Thus, new primer pairs for both species were designed from the internal transcribed spacer region that were highly sensitive and specific for detection of G. citricarpa using DNA recovered from single lesions on fruit by a rapid DNA extraction procedure.

13.
J Bacteriol ; 186(7): 2164-72, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15028702

RESUMO

Leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in accidental hosts, including humans. Complete genome sequencing of Leptospira interrogans serovar Copenhageni and comparative analysis with the available Leptospira interrogans serovar Lai genome reveal that despite overall genetic similarity there are significant structural differences, including a large chromosomal inversion and extensive variation in the number and distribution of insertion sequence elements. Genome sequence analysis elucidates many of the novel aspects of leptospiral physiology relating to energy metabolism, oxygen tolerance, two-component signal transduction systems, and mechanisms of pathogenesis. A broad array of transcriptional regulation proteins and two new families of afimbrial adhesins which contribute to host tissue colonization in the early steps of infection were identified. Differences in genes involved in the biosynthesis of lipopolysaccharide O side chains between the Copenhageni and Lai serovars were identified, offering an important starting point for the elucidation of the organism's complex polysaccharide surface antigens. Differences in adhesins and in lipopolysaccharide might be associated with the adaptation of serovars Copenhageni and Lai to different animal hosts. Hundreds of genes encoding surface-exposed lipoproteins and transmembrane outer membrane proteins were identified as candidates for development of vaccines for the prevention of leptospirosis.


Assuntos
Genoma Bacteriano , Genômica , Leptospira interrogans/fisiologia , Leptospira interrogans/patogenicidade , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Cricetinae , Humanos , Leptospira interrogans/classificação , Leptospira interrogans/genética , Leptospirose/microbiologia , Camundongos , Dados de Sequência Molecular , Análise de Sequência de DNA , Sorotipagem , Virulência/genética
15.
J Bacteriol ; 185(3): 1018-26, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12533478

RESUMO

Xylella fastidiosa is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee. X. fastidiosa has an unusually broad host range, has an extensive geographical distribution throughout the American continent, and induces diverse disease phenotypes. Previous molecular analyses indicated three distinct groups of X. fastidiosa isolates that were expected to be genetically divergent. Here we report the genome sequence of X. fastidiosa (Temecula strain), isolated from a naturally infected grapevine with Pierce's disease (PD) in a wine-grape-growing region of California. Comparative analyses with a previously sequenced X. fastidiosa strain responsible for citrus variegated chlorosis (CVC) revealed that 98% of the PD X. fastidiosa Temecula genes are shared with the CVC X. fastidiosa strain 9a5c genes. Furthermore, the average amino acid identity of the open reading frames in the strains is 95.7%. Genomic differences are limited to phage-associated chromosomal rearrangements and deletions that also account for the strain-specific genes present in each genome. Genomic islands, one in each genome, were identified, and their presence in other X. fastidiosa strains was analyzed. We conclude that these two organisms have identical metabolic functions and are likely to use a common set of genes in plant colonization and pathogenesis, permitting convergence of functional genomic strategies.


Assuntos
Citrus/microbiologia , Gammaproteobacteria/genética , Genoma Bacteriano , Doenças das Plantas/microbiologia , Sequência de Bases , Dados de Sequência Molecular
16.
Plant Dis ; 87(11): 1355-1359, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30812553

RESUMO

Citrus sudden death (CSD) appears to be a new disease that is a serious problem in Brazil. Symptoms of CSD include yellow stain in the phloem of the rootstock. The cause is not known, but it appears to be infectious and may only affect trees budded on Rangpur lime. In a survey in Brazil, in addition to CSD, we observed numerous trees on Rangpur lime that were obviously declining but had remained in production for several years. Trees with this disease, referred to as Rangpur lime decline (RLD) were different from those with citrus blight (CB). They had near-normal size fruit compared with the small fruit associated with CB and were negative in the serological test for the CB-associated protein (p12). Moreover, they did not have the yellow stain symptom and obviously were declining much more slowly than was reported for CSD. To determine what viruses or virus strains might be associated with CSD, double-stranded (ds)RNAs from fibrous roots of a tree with CSD and stem bark from greenhouse trees infected with Citrus tristeza virus (CTV) isolates T30 and T36 were used to make random primed cDNAs. A Clontech PCR-Select cDNA Subtraction Kit was used to subtract the CSD cDNA with cDNA from an equal mixture of dsRNA from T30 and T36. Of 28 clones that were sequenced, five were found to be significantly different from published CTV sequences. One clone (SDA-1) was found to be only 48% similar to CTV T30 based on amino acid sequence. Using samples collected in October 2001, hybridization assays with a DIG probe of SDA-1 were positive for RNA from roots of declining trees from an area where CSD is reported to occur and from a second area where trees were declining with what had been thought to be CB and are now considered to be RLD. The SDA-1 probe reacted weakly or not at all with RNA from stem bark of trees with CSD, collected in October 2001, or RNA from roots of trees that were declining with CB. Using samples collected in March 2003 from trees with severe decline (nearly dead), the SDA-1 probe reacted with all preparations from both stems and roots. Reactions to the SDA-1 probe also were observed in many stem or root samples from trees with RLD, with early symptoms of CSD, and nonsymptomatic trees. The SDA-1 probe did not react with samples from roots or stems of healthy or CB trees from Florida.

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