Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhibition of flower pigmentation in transgenic petunia plants was previously accomplished by expressing an antisense chalcone synthase (chs) gene under the control of the cauliflower mosaic virus (CaMV) 35S promoter. This chimeric gene was not effective in inhibiting pigmentation in anthers, presumably because the viral CaMV 35S promoter was insufficiently expressed in cell types of this organ in which the pigments are produced. Insertion of the anther box, a homologous sequence found in other genes expressed in anthers, resulted in a modified expression pattern driven by this promoter, as monitored by the beta-glucuronidase (gus) gene. In addition to the basic CaMV 35S expression pattern in anthers, GUS activity was observed in tapetum cells when the modified promoter was fused to the gus gene. This promoter construct was subsequently used to drive an antisense chs gene in transgenic petunia, which led to the inhibition of pigment synthesis in anthers of five of 35 transformants. Transgenic plants with white anthers were male sterile due to an arrest in male gametophyte development. This finding indicated that flavonoids play an essential role in male gametophyte development.
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PMID:Antisense inhibition of flavonoid biosynthesis in petunia anthers results in male sterility. 149 95

To establish a genetic system for dissection of light-mediated signal transduction in plants, we analyzed the light wavelengths and promoter sequences responsible for the light-induced expression of the Arabidopsis thaliana chalcone synthase (CHS) promoter fused to the beta-glucuronidase (GUS) marker gene. Transgenic A. thaliana lines carrying 1975, 523, 186, and 17 bp of the CHS promoter fused to the GUS gene were generated, and the expression of these chimeric genes was monitored in response to high intensity light in mature plants and to different wavelengths of light in seedlings. Fusion constructs containing 1975 and 523 bp of CHS promoter sequence behaved identically to the endogenous CHS gene under all conditions. Expression of these constructs was induced specifically in response to high intensity white light and blue light. The response to blue light was seen in the presence of the Pfr form of phytochrome. Fusion constructs containing 186 bp of promoter sequence showed reduced basal levels of expression and only weak stimulation by blue light but were induced significantly by high intensity white light. These analyses showed that the expression of the A. thaliana CHS gene is responsive to a specific blue light receptor and that sequences between -523 and -186 bp are required for optimal basal and blue light-induced expression of this gene. The experiments lay the foundation for a simple genetic screen for light response mutants.
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PMID:High intensity and blue light regulated expression of chimeric chalcone synthase genes in transgenic Arabidopsis thaliana plants. 203 7

A nuclear factor (SBF-1) has previously been identified in Phaseolus vulgaris L. (bean) suspension cell nuclear extracts that binds in vitro to three DNase I-footprinted elements (SBF-1 boxes I, II, and III, 5' to 3') in the 5' region of the bean CHS15 (chalcone synthase) gene promoter. To define the functional role of the three SBF-1 boxes in development, we examined transgenic tobacco plants carrying a series of nested CHS15 promoter-beta-glucuronidase (GUS) fusions for GUS activity by histochemical staining. We show that the CHS15 promoter deleted to position -173 and lacking all three SBF-1 boxes directs the same qualitative pattern of expression in initiating lateral roots and in developing seeds as the full length promoter (-326). Thus, activation of expression in these organs is mediated by sequence elements located downstream of the three SBF-1 boxes. However, specific deletions within the -326 to -173 region modulate expression. Thus, deletion of box II abolishes GUS activity in initiating lateral roots. Further deletion of box III fails to restore expression but subsequent deletion of an additional 43 bp to position -173 re-establishes expression. We show that sequence-specific DNA-binding activities consistent with these results are present in nuclear extracts of bean roots and seeds. These studies reveal cis elements within the CHS15 promoter, and potential trans factors, that permit organ- and tissue-specific developmental patterns of regulation to be combined with a flexible response to environmental cues.
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PMID:Cis elements and potential trans-acting factors for the developmental regulation of the Phaseolus vulgaris CHS15 promoter. 754 34

Transgenic Arabidopsis expressing beta-glucuronidase (GUS) driven by a chalcone synthase gene (CHS) promoter were produced. GUS activity in the leaves increased with increasing fluence rates of white light in parallel with endogenous CHS transcript levels. An isogenic line homozygous for the transgene was obtained and mutagenized seedlings of this line were screened for altered light-induction of the transgene. Putative mutants with low GUS activity were not altered in the light-induction of endogenous CHS transcripts and are therefore not regulatory mutants. Two mutant lines (A12 and C10) with elevated levels of GUS activity in the light show a corresponding increase in CHS transcript levels. The A12 mutant was focussed upon and designated icx1 (increased chalcone synthase expression). This mutant has enhanced light-stimulation of CHS expression since CHS transcript levels in darkness in icx1 are very low, as in the wild-type. The transcript levels of two other genes involved in flavonoid biosynthesis are elevated in the light in icx1 as is anthocyanin formation. However, there is no alteration in LHCII chlorophyll a/b-binding protein gene (CAB) transcript levels under the same conditions. The altered gene expression phenotype of icx1 co-segregates with several other phenotypic characteristics, including fewer leaf trichomes and alterations to the seed coat. On the basis of these data and comparison with the Arabidopsis ttg (transparent testa glabra) mutant, it is suggested that the ICX1 gene product may be concerned both with the light-regulation of gene expression and with developmental processes occurring in the epidermis.
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PMID:Isolation of Arabidopsis mutants altered in the light-regulation of chalcone synthase gene expression using a transgenic screening approach. 755 Mar 75

Common plant regulatory factor 1 (CPRF1) is a parsley basic region/leucine zipper (bZIP) transcription factor that recognizes specific nucleotide sequences containing ACGT cores. Such a sequence is contained within LRU1, the composite light regulatory unit that is necessary and sufficient for light-dependent activity of the parsley chalcone synthase (CHS) promoter. After light treatment of both etiolated and green seedlings, CPRF1 mRNA levels increased prior to CHS mRNA accumulation. The change in CPRF1 mRNA leads to a light-responsive increase in CPRF1 protein. Transient expression analysis in parsley protoplasts using the CPRF1 promoter fused to the beta-glucuronidase (GUS) open reading frame indicated that light-dependent CPRF1 mRNA accumulation was under transcriptional control. The 5' untranslated region of the CPRF1 gene includes a cis-acting nucleotide sequence that contains two ACGT elements at a distance of 12 bp between their palindromic centers. This feature is reminiscent of as-1 and octopine synthase (ocs) elements identified in promoters from plant pathogens. This double ACGT Element element, designated dACECPRF1, stimulated transcription when placed 5' to a heterologous core promoter. CPRF1 bound to dACECPRF1 DNA as well as to the ACGT element from the CHS promoter in vitro. Cotransfection experiments demonstrated that CPRF1 interacts with these elements in vivo and that overexpression of CPRF1 actually reduced light-dependent transcription from the CHS promoter. CPRF1 thus appears to contribute to the regulation of the CPRF1 gene and to interfere with the activities of light-regulated promoters.
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PMID:Functional analysis of a light-responsive plant bZIP transcriptional regulator. 782 94

Carrot cell wall beta-fructosidase, previously purified and cloned, is encoded by a single, wound- and pathogen-inducible gene. The developmental regulation of the gene was studied by determining the steady-state mRNA levels in different organs during carrot development: cell wall beta-fructosidase mRNA was detected in roots and leaves of young plants but not during tap root development. A genomic clone was isolated and characterized. The transcription start site was determined by primer extension analysis. Inspection of the promoter sequence (1488 bp) revealed the presence of sequences with high homology to cis-acting elements for the regulation of plant genes by wounding and infection. The 5'-regulatory sequence was fused to the reporter gene beta-glucuronidase (GUS) and tested in a transient expression assay with carrot suspension cells and wounded carrot root tissue (aged disks of carrot roots). The expression of the GUS gene in the transfected cells proved that the isolated promoter was functional. In transgenic tobacco plants containing the cell wall beta-fructosidase promoter fused to GUS, the reporter gene was predominantly expressed in the shoot and root meristems of young seedlings. No GUS expression was detected in mature tobacco plants, showing that the development-specific regulation of the cell wall beta-fructosidase promoter seen in carrot was maintained in tobacco plants. In contrast, expression of the GUS reporter gene in transgenic tobacco was not wound inducible. To analyze the functional organization of the cell wall beta-fructosidase promoter, a 5'-deletion series was generated and tested in a transient expression assay in protoplasts of Nicotiana plumbaginifolia. Two regions containing putative silencer elements were identified. A comparison of these regions with known silencer elements identified in both regions one copy of the negative dominant cis-acting element found in a chalcone synthase promoter of petunia.
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PMID:Molecular characterization of the gene for carrot cell wall beta-fructosidase. 822 Apr 95

Soybean vspB encodes a highly expressed vegetative storage protein-acid phosphatase. In soybean, vspB expression is stimulated by methyl jasmonate (MeJA) and sugars. The vspB promoter was studied by transforming tobacco with fusions of 5' noncoding vspB DNA and the gene encoding beta-glucuronidase (GUS). Constructs containing 833 bp of vspB 5' DNA showed high expression of GUS in stems, leaf veins and trichomes, sepals, and pollen. Sucrose (0.2 M) and MeJA (10(-5) M) increased gene expression when applied to leaf tissue. Deletion of the region -787 to -520 with respect to the transcription initiation site rendered the vspB promoter noninducible by MeJA but still sucrose responsive. This result indicates that DNA elements capable of modulating vspB by MeJA can be separated from carbon response elements. Further 5' end deletion from -520 to -403 or 3' end deletion from -165 to -289 removed DNA sequences involved in carbon modulation of gene expression. A DNA domain that mediates the MeJA response was further localized to a 50-bp region between -535 and -585. This domain when fused to a cauliflower mosaic virus (CaMV) 35S truncated (-88) promoter makes the CaMV promoter responsive to MeJA. The MeJA-responsive domain contains a G-box motif (CACGTG) and a C-rich sequence. A similar 50-bp DNA region is present in the putative promoter of vspA. Related sequences are located in a wound- and MeJA-responsive domain of the proteinase inhibitor II gene and a UV-responsive promoter domain of chs, the gene encoding chalcone synthase that is also responsive to MeJA.
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PMID:Identification of a methyl jasmonate-responsive domain in the soybean vspB promoter. 846 21

Investigations of phytochrome mutants of Arabidopsis suggested that the expression of chalcone synthase (chs) and anthocyanin accumulation is predominantly controlled by phytochrome A. To test the functionality of phytochrome A and B at the molecular level recombinant, yeast-derived phytochrome-phycocyanobilin adducts (phyA, phyB) and oat phytochrome A (phyA) were microinjected into etiolated aurea tomato seedlings. Subsequent to microinjection anthocyanin and chlorophyll accumulation was monitored as well as beta-glucuronidase (GUS) expression mediated by light-regulated promoters (chs, chlorophyll a/b binding protein (lhcb1) and ferredoxin NADP+ oxidoreductase (fnn). Microinjection of phyA under white light conditions caused anthocyanin and chlorophyll accumulation and mediated chs-GUS, lhcb 1-GUS and fnr-GUS expression. Microinjection of phyB under identical conditions induced chlorophyll accumulation and mediated lhcb 1-GUS and fnr-GUS expression but neither anthocyanin accumulation nor chs-GUS expression were observed. The characterization of Arabidopsis phytochrome mutants and the microinjection experiments suggested that phyB cannot induce the accumulation of juvenile anthocyanin. Microinjections under far-red light conditions demonstrated that phyA can act independently of other photoreceptors. By contrast, phyB injections under red light conditions indicated that phyB needs interactions with other photoreceptors to mediate a rapid and efficient de-etiolation signal.
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PMID:Functional analysis of yeast-derived phytochrome A and B phycocyanobilin adducts. 889 41

UV and blue light stimulate transcription of key flavonoid biosynthesis genes in a range of higher plants. Here, we provide evidence that several distinct "inductive" and "synergistic" UV/blue phototransduction pathways regulate chalcone synthase (CHS) gene transcription and transcript accumulation in Arabidopsis leaf tissue. Experiments with the long-hypocotyl hy4-2.23N mutant showed that separate inductive pathways mediate responses to UV-B and UV-A/blue light. Only the UV-A/blue light induction of CHS expression involved the CRY1 photoreceptor. In addition, UV-A and blue light each act synergistically with UV-B to stimulate CHS transcript accumulation and beta-glucuronidase activity driven by a CHS promoter in transgenic leaf tissue. The UV-A and blue phototransduction pathways responsible for synergism are distinct because they produce transient and relatively stable signals, respectively, and can function additively to stimulate CHS promoter function. The hy4-2.23N mutant retains the synergistic interactions between UV-B and both UV-A and blue light, indicating that neither synergism pathway involves the CRY1 photoreceptor. Our findings reveal considerable complexity in both photoreception and signal transduction in regulating CHS gene expression by UV and blue light.
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PMID:UV-B, UV-A, and blue light signal transduction pathways interact synergistically to regulate chalcone synthase gene expression in Arabidopsis. 898 87

To identify DNA sequences of the Arabidopsis thaliana chalcone synthase gene (CHS) concerned with induction by UV-B and UV-A/blue light, AtCHS promoter constructions were assayed by transient expression in protoplasts prepared from two different lines of cultured A. thaliana cells. The protoplasts responded similarly to A. thaliana leaf tissue in light-dependent CHS transcript accumulation. The reporter enzyme beta-glucuronidase (GUS) was used to monitor light-responsive promoter activity. A 1972 bp promoter conferred UV-B and UV-A/blue light induction of GUS activity. Deletion to 164 bp resulted in reduced promoter strength but retention of responsiveness to UV-B and UV-A/blue light. Further deletion abolished transcriptional activity. The 164 bp promoter contains sequences closely resembling LRUPcCHS, (light-responsive unit of the Petroselinum crispum CHS promoter). This A. thaliana CHS promoter region, designated LRUAtCHS, was sufficient to confer UV-B and UV-A/blue light responsiveness to a heterologous core promoter. Mutation of sequences in LRUAtCHS corresponding to the ACGT element and the MYB recognition element of LRUPcCHS resulted in inactivation of the 164 bp and 335 bp promoter deletions. However, the mutant 668 bp promoter retained residual UV-B and UV-A/blue light-induced expression, indicating the presence of additional functional sequences upstream of -335. Mutation of a single G-box-like sequence around -442 had no effect on light responsiveness, indicating that it does not function in light regulation of this promoter. Since no difference in responsiveness to UV-B and UV-A/blue light was observed with any promoter variant, we conclude that the two phototransduction pathways regulate transcription factors which interact with common promoter elements. The results from-our analysis of a A. thaliana light-responsive promoter will facilitate the study of light-dependent gene regulation by genetic means in Arabidopsis thaliana.
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PMID:Identification of UV/blue light-response elements in the Arabidopsis thaliana chalcone synthase promoter using a homologous protoplast transient expression system. 952 7


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