622 research outputs found
PlantCARE, a plant cis-acting regulatory element database
PlantCARE is a database of plant cis-acting regulatory elements, enhancers and repressors. Besides the transcription motifs found on a sequence, it also offers a link to the EMBL entry that contains the full gene sequence as well as a description of the conditions in which a motif becomes functional. The information on these sites is given by matrices, consensus and individual site sequences on particular genes, depending on the available information
Sl-ERF2, a Tomato Ethylene Response Factor Involved in Ethylene Response and Seed Germination
Ethylene response factors (ERFs) are plant
transcriptional regulators mediating ethylene-dependent gene
expression via binding to the GCC motif found in the
promoter region of ethylene-regulated genes. We report
here on the structural and functional characterization of
the tomato Sl-ERF2 gene that belongs to a distinct class of
the large ERF gene family. Both spliced and unspliced
versions of Sl-ERF2 transcripts were amplified from RNA
samples and the search in the public tomato expressed
sequence tag (EST) database confirmed the existence of
the two transcript species in a number of cDNA libraries. The
unspliced transcript contains two open reading frames
yielding two hypothetical proteins, a small highly truncated
version lacking the APETALA2 domain and a bigger protein
lacking the N-terminal MCGGAAII/L consensus peptide
specific to ERF members from subfamily IV. Nevertheless,
functional Sl-ERF2 protein may only derive from spliced
transcripts since, depending on the tissue, the level of the
spliced transcript is much higher than that of the unspliced
transcript. Sl-ERF2 is expressed in all plant tissues
tested, though its transcript accumulates preferentially in
germinating seeds and ripening fruit. Overexpression of the
Sl-ERF2 gene in transgenic tomato lines results in premature
seed germination and enhanced hook formation of darkgrown
seedlings, which is indicative of increased ethylene
sensitivity. The expression of the mannanase2 gene is
upregulated in Sl-ERF2-overexpressing seeds, suggesting
that Sl-ERF2 stimulates seed germination through the
induction of the mannanase2 gene. It is noteworthy that
the exaggerated hook phenotype is abolished when ethylene
perception is blocked, strongly suggesting that Sl-ERF2
requires other ethylene-dependent components to impact the
hook formation process
Exploring transcriptional signalling mediated by OsWRKY13, a potential regulator of multiple physiological processes in rice
BACKGROUND Rice transcription regulator OsWRKY13 influences the functioning of more than 500 genes in multiple signalling pathways, with roles in disease resistance, redox homeostasis, abiotic stress responses, and development. RESULTS To determine the putative transcriptional regulation mechanism of OsWRKY13, the putative cis-acting elements of OsWRKY13-influenced genes were analyzed using the whole genome expression profiling of OsWRKY13-activated plants generated with the Affymetrix GeneChip Rice Genome Array. At least 39 transcription factor genes were influenced by OsWRKY13, and 30 of them were downregulated. The promoters of OsWRKY13-upregulated genes were overrepresented with W-boxes for WRKY protein binding, whereas the promoters of OsWRKY13-downregulated genes were enriched with cis-elements putatively for binding of MYB and AP2/EREBP types of transcription factors. Consistent with the distinctive distribution of these cis-elements in up- and downregulated genes, nine WRKY genes were influenced by OsWRKY13 and the promoters of five of them were bound by OsWRKY13 in vitro; all seven differentially expressed AP2/EREBP genes and six of the seven differentially expressed MYB genes were suppressed by in OsWRKY13-activated plants. A subset of OsWRKY13-influenced WRKY genes were involved in host-pathogen interactions. CONCLUSION These results suggest that OsWRKY13-mediated signalling pathways are partitioned by different transcription factors. WRKY proteins may play important roles in the monitoring of OsWRKY13-upregulated genes and genes involved in pathogen-induced defence responses, whereas MYB and AP2/EREBP proteins may contribute most to the control of OsWRKY13-downregulated genes.This work was supported by grants from the National Program of High Technology Development of China, the National Program on the Development of Basic Research in China, and the National Natural Science Foundation of China
Carrot AOX2a transcript profile responds to growth and chilling exposure
Alternative oxidase (AOX) is a key enzyme of the alternative respiration, known to be
involved in plant development and in response to various stresses. To verify the role of DcAOX1 and
DcAOX2a genes in carrot tap root growth and in response to cold stress, their expression was analyzed
in two experiments: during root growth for 13 weeks and in response to a cold challenge trial of
7 days, in both cases using different carrot cultivars. Carrot root growth is initially characterized by an
increase in length, followed by a strong increase in weight. DcAOX2a presented the highest expression
levels during the initial stages of root growth for all cultivars, but DcAOX1 showed no particular
trend in expression. Cold stress had a negative impact on root growth, and generally up-regulated
DcAOX2a with no consistent effect on DcAOX1. The identification of cis-acting regulatory elements
(CAREs) located at the promoters of both genes showed putative sequences involved in cold stress
responsiveness, as well as growth. However, DcAOX2a promoter presented more CAREs related to
hormonal pathways, including abscisic acid and gibberellins synthesis, than DcAOX1. These results
point to a dual role of DcAOX2a on carrot tap root secondary growth and cold stress responseinfo:eu-repo/semantics/publishedVersio
Isolation and functional characterization of a cotton ubiquitination-related promoter and 5'UTR that drives high levels of expression in root and flower tissues
<p>Abstract</p> <p>Background</p> <p>Cotton (<it>Gossypium </it>spp.) is an important crop worldwide that provides raw material to 40% of the textile fiber industry. Important traits have been studied aiming the development of genetically modified crops including resistance to insect and diseases, and tolerance to drought, cold and herbicide. Therefore, the characterization of promoters and regulatory regions is also important to achieve high gene expression and/or a specific expression pattern. Commonly, genes involved in ubiquitination pathways are highly and differentially expressed. In this study, we analyzed the expression of a cotton ubiquitin-conjugating enzyme (E2) family member with no previous characterization.</p> <p>Results</p> <p>Nucleotide analysis revealed high identity with cotton <it>E2 </it>homologues. Multiple alignment showed a premature stop codon, which prevents the encoding of the conserved cysteine residue at the <it>E2 </it>active site, and an intron that is spliced in <it>E2 </it>homologues, but not in <it>GhGDRP85</it>. The <it>GhGDRP85 </it>gene is highly expressed in different organs of cotton plants, and has high transcript levels in roots. Its promoter (uceApro2) and the 5'UTR compose a regulatory region named uceA1.7, and were isolated from cotton and studied in <it>Arabidopsis thaliana</it>. uceA1.7 shows strong expression levels, equaling or surpassing the expression levels of CaMV35S. The uceA1.7 regulatory sequence drives GUS expression 7-fold higher in flowers, 2-fold in roots and at similar levels in leaves and stems. GUS expression levels are decreased 7- to 15-fold when its 5'UTR is absent in uceApro2.</p> <p>Conclusions</p> <p>uceA1.7 is a strong constitutive regulatory sequence composed of a promoter (uceApro2) and its 5'UTR that will be useful in genetic transformation of dicots, having high potential to drive high levels of transgene expression in crops, particularly for traits desirable in flower and root tissues.</p
Differential expression of cysteine desulfurases in soybean
Background: Iron-sulfur [Fe-S] clusters are prosthetic groups required to sustain fundamental life processes including electron transfer, metabolic reactions, sensing, signaling, gene regulation and stabilization of protein structures. In plants, the biogenesis of Fe-S protein is compartmentalized and adapted to specific needs of the cell. Many environmental factors affect plant development and limit productivity and geographical distribution. The impact of these limiting factors is particularly relevant for major crops, such as soybean, which has worldwide economic importance. Results: Here we analyze the transcriptional profile of the soybean cysteine desulfurases NFS1, NFS2 and ISD11 genes, involved in the biogenesis of [Fe-S] clusters, by quantitative RT-PCR. NFS1, ISD11 and NFS2 encoding two mitochondrial and one plastid located proteins, respectively, are duplicated and showed distinct transcript levels considering tissue and stress response. NFS1 and ISD11 are highly expressed in roots, whereas NFS2 showed no differential expression in tissues. Cold-treated plants showed a decrease in NFS2 and ISD11 transcript levels in roots, and an increased expression of NFS1 and ISD11 genes in leaves. Plants treated with salicylic acid exhibited increased NFS1 transcript levels in roots but lower levels in leaves. In silico analysis of promoter regions indicated the presence of different cis-elements in cysteine desulfurase genes, in good agreement with differential expression of each locus. Our data also showed that increasing of transcript levels of mitochondrial genes, NFS1/ISD11, are associated with higher activities of aldehyde oxidase and xanthine dehydrogenase, two cytosolic Fe-S proteins. Conclusions: Our results suggest a relationship between gene expression pattern, biochemical effects, and transcription factor binding sites in promoter regions of cysteine desulfurase genes. Moreover, data show proportionality between NFS1 and ISD11 genes expression
Internet Resources for Gene Expression Analysis in Arabidopsis thaliana
The number of online databases and web-tools for gene expression analysis in Arabidopsis thaliana has increased tremendously during the last years. These resources permit the database-assisted identification of putative cis-regulatory DNA sequences, their binding proteins, and the determination of common cis-regulatory motifs in coregulated genes. DNA binding proteins may be predicted by the type of cis-regulatory motif. Further questions of combinatorial control based on the interaction of DNA binding proteins and the colocalization of cis-regulatory motifs can be addressed. The database-assisted spatial and temporal expression analysis of DNA binding proteins and their target genes may help to further refine experimental approaches. Signal transduction pathways upstream of regulated genes are not yet fully accessible in databases mainly because they need to be manually annotated. This review focuses on the use of the AthaMap and PathoPlant® databases for gene expression regulation analysis and discusses similar and complementary online databases and web-tools. Online databases are helpful for the development of working hypothesis and for designing subsequent experiments
Evaluating Potential Plant Hormone Cross Talk between Auxin and Ethylene in Arabidopsis
Auxin is the primary hormone responsible for plant growth and development. Regulation of auxin-response genes occurs through transcriptional activators (auxin response factors called ARFs) which bind to auxin response elements (AuxREs). Some auxin-responsive genes encode aminocyclopropane-1-carboxylic acid synthase (ACS) enzymes which regulate the production of the plant hormone ethylene. The major research objective was to evaluate transcriptional cross talk between auxin and ethylene. Both AuxREs and ethylene response elements were found in several ACS and ARF genes, suggesting cross talk between the two hormones at the transcriptional level. Analysis of transgenic Arabidopsis thaliana plants deficient in ARF7 and containing a reporter gene for the ACS5 expression were used to evaluate cross talk supports ARF7 regulation of ACS5 expression after auxin treatment in dark-grown seedlings and during flower development in light-grown seedlings, but do not show a strong association with gravitropism and wounding responses
Genome-wide investigation of light and carbon signaling interactions in Arabidopsis
BACKGROUND: Light and carbon are two essential signals influencing plant growth and development. Little is known about how carbon and light signaling pathways intersect or influence one another to affect gene expression. RESULTS: Microarrays are used to investigate carbon and light signaling interactions at a genome-wide level in Arabidopsis thaliana. A classification system, 'InterAct Class', is used to classify genes on the basis of their expression profiles. InterAct classes and the genes within them are placed into theoretical models describing interactions between carbon and light signaling. Within InterAct classes there are genes regulated by carbon (201 genes), light (77 genes) or through carbon and light interactions (1,247 genes). We determined whether genes involved in specific biological processes are over-represented in the population of genes regulated by carbon and/or light signaling. Of 29 primary functional categories identified by the Munich Information Center for Protein Sequences, five show over-representation of genes regulated by carbon and/or light. Metabolism has the highest representation of genes regulated by carbon and light interactions and includes the secondary functional categories of carbon-containing-compound/carbohydrate metabolism, amino-acid metabolism, lipid metabolism, fatty-acid metabolism and isoprenoid metabolism. Genes that share a similar InterAct class expression profile and are involved in the same biological process are used to identify putative cis elements possibly involved in responses to both carbon and light signals. CONCLUSIONS: The work presented here represents a method to organize and classify microarray datasets, enabling one to investigate signaling interactions and to identify putative cis elements in silico through the analysis of genes that share a similar expression profile and biological function
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