Xylella fastidiosa
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA12325 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| Other | ||||
| SRR10418555_1.fastq.gz | Fastqsanger.gz | |||
| SRR10418555_2.fastq.gz | Fastqsanger.gz | |||
| SRR10418556_1.fastq.gz | Fastqsanger.gz | |||
| SRR10418556_2.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:The causal agent of citrus variegated chlorosis
| PRJNA17823 | ENA
Project description:Xylella fastidiosa is the etiologic agent of a wide range of plant diseases including citrus variegated chlorosis (CVC), a major threat to the Brazilian citrus industry. Genome sequences of several strains of this phytopathogen are accessible, enabling large-scale functional studies. Transcript levels in different iron availabilities were assessed with DNA microarrays representing 2608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c. When treated with the iron chelator 2,2-dipyridyl, 193 CDS were considered as up-regulated and 216 as down-regulated. In the presence of 100uM of ferric pyrophosphate, 218 and 256 CDS were considered as up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription - quantitative PCR that showed a Pearson correlation of 0.77 with array results. The CDS differentially expressed upon the iron concentration shift participate in diverse cellular functions. Many CDS involved with regulatory functions, pathogenicity and cell structure, were modulated in both conditions tested suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to pili/fimbriae functions. We also investigated the contribution of the ferric uptake regulator Fur to the iron regulon of X. fastidiosa. The promoter regions of strain 9a5c genome were screened for putative Fur boxes and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron regulon of X. fastidiosa and present novel evidence for iron regulation of pathogenicity determinants. Direct comparison between high iron content (100uM ferric pyrophosphate) and control condition. Hybridizations are dye-swaped. There are 2 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2007-09-01 | E-GEOD-5886 | biostudies-arrayexpress
Project description:Xylella fastidiosa is the etiologic agent of a wide range of plant diseases including citrus variegated chlorosis (CVC), a major threat to the Brazilian citrus industry. Genome sequences of several strains of this phytopathogen are accessible, enabling large-scale functional studies. Transcript levels in different iron availabilities were assessed with DNA microarrays representing 2608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c. When treated with the iron chelator 2,2-dipyridyl, 193 CDS were considered as up-regulated and 216 as down-regulated. In the presence of 100uM of ferric pyrophosphate, 218 and 256 CDS were considered as up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription - quantitative PCR that showed a Pearson correlation of 0.77 with array results. The CDS differentially expressed upon the iron concentration shift participate in diverse cellular functions. Many CDS involved with regulatory functions, pathogenicity and cell structure, were modulated in both conditions tested suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to pili/fimbriae functions. We also investigated the contribution of the ferric uptake regulator Fur to the iron regulon of X. fastidiosa. The promoter regions of strain 9a5c genome were screened for putative Fur boxes and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron regulon of X. fastidiosa and present novel evidence for iron regulation of pathogenicity determinants. Keywords: stress response; response to iron-depleted condition
2007-09-01 | GSE5888 | GEO
Project description:Xylella fastidiosa is the etiologic agent of a wide range of plant diseases including citrus variegated chlorosis (CVC), a major threat to the Brazilian citrus industry. Genome sequences of several strains of this phytopathogen are accessible, enabling large-scale functional studies. Transcript levels in different iron availabilities were assessed with DNA microarrays representing 2608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c. When treated with the iron chelator 2,2-dipyridyl, 193 CDS were considered as up-regulated and 216 as down-regulated. In the presence of 100uM of ferric pyrophosphate, 218 and 256 CDS were considered as up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription - quantitative PCR that showed a Pearson correlation of 0.77 with array results. The CDS differentially expressed upon the iron concentration shift participate in diverse cellular functions. Many CDS involved with regulatory functions, pathogenicity and cell structure, were modulated in both conditions tested suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to pili/fimbriae functions. We also investigated the contribution of the ferric uptake regulator Fur to the iron regulon of X. fastidiosa. The promoter regions of strain 9a5c genome were screened for putative Fur boxes and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron regulon of X. fastidiosa and present novel evidence for iron regulation of pathogenicity determinants. Keywords: stress response; response to iron-replete condition
2007-09-01 | GSE5886 | GEO
Project description:Xylella fastidiosa is the etiologic agent of a wide range of plant diseases including citrus variegated chlorosis (CVC), a major threat to the Brazilian citrus industry. Genome sequences of several strains of this phytopathogen are accessible, enabling large-scale functional studies. Transcript levels in different iron availabilities were assessed with DNA microarrays representing 2608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c. When treated with the iron chelator 2,2-dipyridyl, 193 CDS were considered as up-regulated and 216 as down-regulated. In the presence of 100uM of ferric pyrophosphate, 218 and 256 CDS were considered as up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription - quantitative PCR that showed a Pearson correlation of 0.77 with array results. The CDS differentially expressed upon the iron concentration shift participate in diverse cellular functions. Many CDS involved with regulatory functions, pathogenicity and cell structure, were modulated in both conditions tested suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to pili/fimbriae functions. We also investigated the contribution of the ferric uptake regulator Fur to the iron regulon of X. fastidiosa. The promoter regions of strain 9a5c genome were screened for putative Fur boxes and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron regulon of X. fastidiosa and present novel evidence for iron regulation of pathogenicity determinants. Keywords: stress response; response to iron-depleted condition Direct comparison between low iron content (200uM 2,2-dipyridyl) and control condition. Hybridizations are dye-swaped. There are 2 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2007-08-31 | E-GEOD-5888 | biostudies-arrayexpress
Project description:Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa, is an important citrus disease that produces chlorotic injuries on leaves and reduced fruit size. This bacterium colonizes plant xylem, thereby interrupting sap flow. Other disease symptoms depend on environmental factors, since asymptomatic and symptomatic CVC plants may be genetically similar. The endophytic microbiome comprises many microbial species that may interact with pathogens, reducing disease symptoms and improving plant growth. However, the genetic and physiological mechanisms that underlie this interaction are largely unknown. In this study, the citrus endophytic bacterium Methylobacterium mesophilicum SR1.6/6 was isolated from healthy plants. This bacterium was able to colonize citrus xylem and could be transferred from plant to plant by Bucephalogonia xanthopis (Insecta), suggesting that this endophytic bacterium may interact with X. fastidiosa in planta, as a result of co-transmission by the same insect vector. To better understand how X. fastidiosa genetic responds to the presence of M. mesophilicum in the same environment, we used microarrays to evaluate the transcriptional profile of X. fastidiosa, after in vitro co-cultivation with M. mesophilicum SR1.6/6. The results showed that during co-cultivation with M. mesophilicum, X. fastidiosa downregulated genes related to growth, while genes related to energy production (cellular respiration) and transport were upregulated. Moreover, X. fastidiosa modulates genes associated with molecular recognition, nutrient competition and the stress response, suggesting the existence of a specific adaptive response to the presence of M. mesophilicum in the culture medium
2014-04-18 | GSE56901 | GEO
Project description:Xyllela fastidiosa (Xf) is a xylem-limited bacterium responsible for important plant diseases, such as citrus variegated chlorosis (CVC) in Brazil and grapevines Pierce´s disease in the USA. One intriguing aspect of this microorganism is its capacity to grow in an extremely harsh environment such as the xylem, mainly composed of water, minerals and few organic salts. In vitro growth of Xf cells in chemically-defined media that mimic xylem fluid has been recently achieved, allowing more detailed studies of metabolic processes used by xylem-dwelling bacteria to thrive in such a nutrient-poor environment. We employed microarray hybridization experiments to compare the transcriptomes of Xf cells grown in 3G10-R, a medium that resembles grape sap and in Periwinkle Wilt (PW), the complex medium traditionally used to cultivate Xf. We identified 317 transcripts modulated in response to growth in either of the two media. Some of these genes seem to be involved in plant colonization, virulence and competition with other microorganisms, and have also been shown, in independent studies, to be up-regulated in cells directly isolated from the xylem of infected plants. Xf cells also show an increase in aerobic respiration when cultivated in PW, which can be associated with enhanced bacterial growth rates. This finding raises the question of weather such a metabolic switch might be related to the onset of CVC in infected plants, when Xf population seems to increase dramatically. Keywords: Diefential growth conditions
2006-12-30 | GSE6619 | GEO
Project description:Background: Xylella fastidiosa, a Gram-negative fastidious bacterium, grows exclusively in the xylem of several plants, causing diseases such as citrus variegated chlorosis. As the xylem sap contains low concentrations of amino acids and other compounds, X. fastidiosa needs to cope with nitrogen limitation in its natural habitat. Results: In this work, we performed a whole-genome microarray analysis of the X. fastidiosa nitrogen starvation response. A time-course experiment (2, 8 and 12 hours) revealed many differentially expressed genes under nitrogen starvation, such as genes related to transport, nitrogen assimilation, amino acid biosynthesis, transcriptional regulation, and many genes encoding hypothetical proteins. In addition, a decrease in the expression levels of many genes involved in carbon metabolism and energy generation pathways was also observed. Comparison of gene expression profiles between the wild type strain and the rpoN null mutant allowed the identification of genes induced by nitrogen starvation in a σ54-dependent manner. A more complete picture of the σ54 regulon was achieved by combining the transcriptome data with an in silico search for potential σ54-dependent promoters, using a position weight matrix approach. One of these σ54-predicted binding sites, located upstream of the glnA gene (encoding a glutamine synthetase), was validated by primer extension assays, confirming that this gene has a σ54-dependent promoter and contains a predicted NtrC binding site. Conclusions: Together, these results show that nitrogen starvation causes intense changes in the X. fastidiosa transcriptome and some of these differentially expressed genes belong to the σ54 regulon.
2010-12-21 | GSE21647 | GEO
Project description:With the aid of a biochip, carrying representative sequences from approximately 2200 sequences from the genome of isolate 9a5c from X. fastidiosa (Xf), microarray-based comparisons have been performed with 6 different Xf isolates obtained from citrus plants (Table 1). Four of these isolates (56a, 9.12c, 187b, and 36f) were obtained from CVC-affected trees and are representatives of the most prevalent Xf haplotypes found in sweet orange orchards across the state of São Paulo, while isolate CV21 was obtained from a non-symptomatic tree from the same region. Isolate Fb7, on the other hand, was obtained from a sweet orange tree that displayed symptoms of “Pecosita”, a disease similar to CVC that occurs in some citrus-growing regions of Argentina. Keywords: Comparative Genomic Hybridization
2007-07-18 | GSE8493 | GEO
Project description:Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa, is an important citrus disease that produces chlorotic injuries on leaves and reduced fruit size. This bacterium colonizes plant xylem, thereby interrupting sap flow. Other disease symptoms depend on environmental factors, since asymptomatic and symptomatic CVC plants may be genetically similar. The endophytic microbiome comprises many microbial species that may interact with pathogens, reducing disease symptoms and improving plant growth. However, the genetic and physiological mechanisms that underlie this interaction are largely unknown. In this study, the citrus endophytic bacterium Methylobacterium mesophilicum SR1.6/6 was isolated from healthy plants. This bacterium was able to colonize citrus xylem and could be transferred from plant to plant by Bucephalogonia xanthopis (Insecta), suggesting that this endophytic bacterium may interact with X. fastidiosa in planta, as a result of co-transmission by the same insect vector. To better understand how X. fastidiosa genetic responds to the presence of M. mesophilicum in the same environment, we used microarrays to evaluate the transcriptional profile of X. fastidiosa, after in vitro co-cultivation with M. mesophilicum SR1.6/6. The results showed that during co-cultivation with M. mesophilicum, X. fastidiosa downregulated genes related to growth, while genes related to energy production (cellular respiration) and transport were upregulated. Moreover, X. fastidiosa modulates genes associated with molecular recognition, nutrient competition and the stress response, suggesting the existence of a specific adaptive response to the presence of M. mesophilicum in the culture medium To evaluate and compare the Xylella fastidiosa 9a5c transcriptome profiles from bacteria cultured in PW and in co-cultive with Methylobacterium mesophilicum SR1.6/6, bacterial cultures were harvested for total RNA extraction after 24h of inoculation. Samples from the resulting RNAs were then used in competitive hybridizations against Xf microarrays. Replicated experiments were performed with RNA preparations from cells in each treatment and since each microarray carried two replicas of each spotted gene, we ended up with a series of 4 independent readings for each gene present in the microarrays. Images were analyzed with the TIGR Spotfinder program (v.2.2.4). All spots with median values lower than the median local background plus two Standard Deviations have been flagged and excluded from further analyses. Replicated experiments were performed with two independent RNA preparations from cells cultivated in each medium. For each pair of RNA preparations, two independent hybridizations were performed, with dye swaps within each pair. The results from each hybridization were submitted to a series of mathematical transformations with the aid of the software TIGR MIDAS v.2.19. These included filtering out all spots whose integrated intensities were below 10,000 a/d units, normalization between the two channels with the aid of the Lowess algorithm and SD regularization of the Cy5/Cy3 ratios across all sectors (blocks) of the array. Finally, the results from each individual experiment were loaded into the software TIGR Multi-Experiment Viewer (TMEV), v.3.01. Experiments were then normalized and genes that displayed statistically significant modulation were identified with the aid of the one-class option of the Significance Analysis of Microarrays (SAM) test, described by Tusher et al. (2001). The δ factor of the SAM test was adjusted to guarantee a False Discovery Rate (FDR) < 1.
2014-04-18 | E-GEOD-56901 | biostudies-arrayexpress