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)

The S-locus glycoprotein gene of Brassica is derived from the genetic locus that controls the self-incompatibility response and the specific recognition between pollen and stigma. The promoter of this gene was used to direct expression of the diphtheria toxin A chain gene and the Escherichia coli beta-glucuronidase gene in transgenic Nicotiana tabacum. Expression of the promoter in cells of the pistil and in pollen suggests that a single gene may direct the self-incompatibility response in the two interacting cell types. Additionally, the fusion genes were expressed gametophytically in the heterologous host species, Nicotiana, rather than sporophytically as expected for Brassica. Thus, although the genes involved in self-incompatibility in Brassica and Nicotiana are not homologous in their coding regions, signals for expression of these genes are apparently conserved between the two genera. Our analysis of toxic gene fusion transformants shows that genetic ablation is useful for probing developmental processes and for studying temporal and spatial patterns of gene expression in plants.
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PMID:A Brassica S-locus gene promoter targets toxic gene expression and cell death to the pistil and pollen of transgenic Nicotiana. 198 17

The S locus glycoprotein (SLG) gene of Brassica encodes stigmatic glycoproteins that are implicated in the pollen-stigma interaction of self-incompatibility. We have transformed the related plant Arabidopsis thaliana with a chimaeric gene consisting of the promoter region of an SLG gene fused to the reporter gene beta-glucuronidase (GUS). In transgenic plants the gene was expressed in two cell types of the flower. In stigmas, the timing and distribution of GUS activity was similar to that previously described for SLG expression in Brassica. In anthers, expression was detected at an earlier stage of flower development with GUS activity restricted to the tapetal cell layer. The novel finding of SLG-promoter activity in the anther supports the hypothesis that sporophytic control of self-incompatibility is a result of SLG-gene expression in the tapetum.
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PMID:A Brassica S locus gene promoter directs sporophytic expression in the anther tapetum of transgenic Arabidopsis. 199 65

The synthesis of mevalonate, which is considered the first rate-limiting step in isoprenoid biosynthesis, is catalyzed by the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR; EC 1.1.1.34). In Arabidopsis, HMGR is encoded by two differentially expressed genes (HMG1 and HMG2). The transcriptional activity of the HMG2 gene was studied after fusing different regions of its 5' flanking region to the beta-glucuronidase (GUS) reporter gene and transforming the resulting constructs into tobacco plants. The spatial and temporal expression directed by the HMG2 promoter in the transgenic plants is consistent with the expression pattern previously established by RNA analysis using an HMG2-specific probe. HMG2 expression is restricted to meristematic (root tip and shoot apex) and floral (secretory zone of the stigma, mature pollen grains, gynoecium vascular tissue, and fertilized ovules) tissues. Deletion analysis of the HMG2 5' flanking region was conducted in transgenic plants and transfected protoplasts. The region containing nucleotides -857 to +64 of the HMG2 gene was sufficient to confer high levels of expression in both floral and meristematic tissues, although deletion to nucleotide -503 resulted in almost complete loss of expression. Sequences contained within the 5' transcribed, untranslated region are also important for gene expression. The biological significance of the restricted pattern of expression of HMG2 is also discussed.
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PMID:Expression of the Arabidopsis HMG2 gene, encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase, is restricted to meristematic and floral tissues. 778 Mar 5

Deletions were made in the promoter of the acyl carrier protein (ACP) Acll.2 gene from Arabidopsis to investigate the nature of the cis-acting elements that direct its expression. These constructs, which included the untranslated leader region, were fused to a reporter gene coding for beta-glucuronidase (GUS) and transformed into tobacco. Quantitative fluorometric analysis of GUS activity in transgenic plants showed that expression in young leaves drops to a basal level when a 85 bp domain, from -320 to -236 relative to transcription initiation, is deleted. Maximum promoter activity in roots also depends on this domain, but two other regions are also important. In total, deletion of the sequences from -466 to -55 caused an ca. 80-fold reduction in Acl1.2 promoter activity in roots. The -320 to -236 domain forms a complex with a protein factor found in leaves and roots, which was not detectable in seeds. The formation of this protein-DNA complex was abolished by mutation of a bZIP core motif, ACGT, found within the context AAGACGTAG, which is dissimilar to the other bZIP-binding sites thus far characterized in plants. Previously we showed that Acl1.2 promoter activity is highest in seeds [2]. Here we find, in contrast to leaves and roots, that deletion to position -236 has no effect on GUS levels in seeds. However, nearly a 100-fold drop was observed when the -235 to -55 region was removed. Hence, this 180 bp domain contains all the cis-acting information necessary for Acl1.2 promoter activity in seeds. The same region is necessary for Acl1.2 activity in the receptacle, stigma, tapetum and pollen of the flower, as demonstrated by histochemical staining.
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PMID:Identification of domains in an Arabidopsis acyl carrier protein gene promoter required for maximal organ-specific expression. 785 29

In legumes, the synthesis of infection- and elicitor-inducible antimicrobial phytoalexins occurs via the isoflavonoid branch of the phenylpropanoid pathway. To study transcriptional regulation of isoflavonoid pathway-specific genes, we have isolated the gene encoding isoflavone reductase (IFR), which is the enzyme that catalyzes the penultimate step in the synthesis of the phytoalexin medicarpin in alfalfa. Chimeric gene fusions were constructed between 765- and 436-bp promoter fragments of the IFR gene and the beta-glucuronidase reporter gene and transferred to alfalfa and tobacco by Agrobacterium-mediated transformation. Both promoter fragments conferred elicitor-mediated expression in cell suspension cultures derived from transgenic plants of both species and fungal infection-mediated expression in leaves of transgenic alfalfa. Developmental expression directed by both promoter fragments in transgenic alfalfa was observed only in the root meristem, cortex, and nodules, which is consistent with the accumulation of endogenous IFR transcripts. However, in transgenic tobacco, expression from the 765-bp promoter was observed in vegetative tissues (root meristem and cortex, inner vascular tissue of stems and petioles, leaf tips, and stem peripheries adjacent to petioles) and in reproductive tissues (stigma, placenta, base of the ovary, receptacle, seed, tapetal layer, and pollen grains), whereas the 436-bp promoter was expressed only in fruits, seed, and pollen. These data indicate that infection/elicitor inducibility of the IFR promoter in both species and developmental expression in alfalfa are determined by sequences downstream of position -436, whereas sequences between -436 and -765 confer a complex pattern of strong ectopic developmental expression in the heterologous species that lacks the isoflavonoid pathway.
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PMID:The elicitor-inducible alfalfa isoflavone reductase promoter confers different patterns of developmental expression in homologous and heterologous transgenic plants. 786 24

Nonspecific lipid transfer proteins (LTPs) from plants are characterized by their ability to stimulate phospholipid transfer between membranes in vitro. However, because these proteins are generally located outside of the plasma membrane, it is unlikely that they have a similar role in vivo. As a step toward identifying the function of these proteins, one of several LTP genes from Arabidoposis has been cloned and the expression pattern of the gene has been examined by analysis of the tissue specificity of beta-glucuronidase (GUS) activity in transgenic plants containing LTP promoter-GUS fusions and by in situ mRNA localization. The LTP1 promoter was active early in development in protoderm cells of embryos, vascular tissues, lignified tips of cotyledons, shoot meristem, and stipules. In adult plants, the gene was expressed in epidermal cells of young leaves and the stem. In flowers, expression was observed in the epidermis of all developing influorescence and flower organ primordia, the epidermis of the siliques and the outer ovule wall, the stigma, petal tips, and floral nectaries of mature flowers, and the petal/sepal abscission zone of mature siliques. The presence of GUS activity in guard cells, lateral roots, pollen grains, leaf vascular tissue, and internal cells of stipules and nectaries was not confirmed by in situ hybridizations, supporting previous observations that suggest that the reporter gene is subject to artifactual expression. These results are consistent with a role for the LTP1 gene product in some aspect of secretion or deposition of lipophilic substances in the cell walls of expanding epidermal cells and certain secretory tissues. The LTP1 promoter region contained sequences homologous to putative regulatory elements of genes in the phenylpropanoid biosynthetic pathway, suggesting that the expression of the LTP1 gene may be regulated by the same or similar mechanisms as genes in the phenylpropanoid pathway.
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PMID:Tissue-specific expression of a gene encoding a cell wall-localized lipid transfer protein from Arabidopsis. 802 57

The promoter of the S Locus Glycoprotein (SLG) gene of Brassica is a tightly regulated promoter that is active specifically in reproductive organs. In transgenic tobacco, this promoter is active exclusively in cells of the pistil and in pollen. We transformed tobacco with truncated versions of the SLG13 promoter fused to the beta-glucuronidase reporter gene. We show that the promoter has a modular organization and consists of separable DNA elements that independently specify pistil- and pollen-specific expression. A 196-bp region (-339 to -143) is sufficient to confer stigma and style specificity to the marker gene. Two distinct, but functionally redundant, domains (-415 to -291 and -117 to -8) allow specific expression of the gene in pollen. The functional domains identified within the SLG13 promoter contain sequence elements that are highly conserved in different alleles of the SLG gene and in the S Locus Related SLR1 gene.
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PMID:Distinct cis-acting elements direct pistil-specific and pollen-specific activity of the Brassica S locus glycoprotein gene promoter. 840 Aug 68

The expression of an Arabidopsis acyl carrier protein (ACP) gene promoter has been examined in transgenic tobacco plants by linking it to the reporter gene beta-glucuronidase (GUS). Fluorometric analysis showed that the ACP gene promoter was most active in developing seeds. Expression was also high in roots, but significantly lower in young leaves and downregulated upon their maturation. Etiolated and light-grown seedlings showed the same level of GUS activity, indicating that this promoter is not tightly regulated by light. Histochemical studies revealed that expression was usually highest in apical/meristematic zones of vegetative tissues. Young flowers (ca. 1 cm in length) showed GUS staining in nearly all cell types, however, cell-specific patterns emerged in more mature flowers. The ACP gene promoter was active in the stigma and transmitting tissue of the style, as well as in the tapetum of the anther, developing pollen, and ovules. The results provide evidence that this ACP gene is regulated in a complex manner and is responsive to the array of signals which accompany cell differentiation, and a demand for fatty acids and lipids, during organogenesis.
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PMID:Developmental regulation of an acyl carrier protein gene promoter in vegetative and reproductive tissues. 850 28

The 14-3-3 proteins, originally described as mammalian brain proteins, are ubiquitous in eukaryotes. We isolated an Arabidopsis 14-3-3 gene, designated GRF1-GF14 chi (for general regulatory factor1-G-box factor 14-3-3 homolog isoform chi), and characterized its expression within plant tissues. Sequence comparison of the GRF1-GF14 chi genomic clone with other 14-3-3 proteins demonstrated that the extreme conservation of 14-3-3 residues in several domains is encoded by the first three exons. The highly variable C-terminal domain is encoded by a divergent fourth exon that is unique among 14-3-3 homologs, suggesting that exon shuffling might confer gene-specific functions among the isoforms. The anatomical distribution and developmental expression of the Arabidopsis 14-3-3 protein were examined in transgenic plants carrying a GRF1-GF14 chi promoter-beta-glucuronidase construct. GF14 chi promoter activity was observed in the roots of both seedlings and mature plants. In immature flowers, GF14 chi promoter activity was localized to the buds. However, as the flowers matured, GF14 chi promoter activity was restricted to the stigma, anthers, and pollen. In immature siliques, GF14 chi promoter activity was initially localized to styles and abscission zones but was subsequently observed throughout mature siliques. In situ hybridization demonstrated that GF14 chi mRNA expression was prominent in epidermal tissue of roots, petals, and sepals of flower buds, papillae cells of flowers, siliques, and endosperm of immature seeds. Thus, plant 14-3-3 gene expression exhibits cell- and tissue-specific localization rivaling that observed for 14-3-3 proteins within the mammalian brain.
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PMID:Molecular organization and tissue-specific expression of an Arabidopsis 14-3-3 gene. 877 94

The expression of two closely related peroxidase isogenes, Shpx6a and Shpx6b, of the legume Stylosanthes humilis was studied using isogene-specific reverse transcriptase PCR techniques. Results indicated that transcripts of both genes were rapidly induced following inoculation with the fungal pathogen Colletotrichum gloeosporioides, wounding and treatment with the defense regulator methyl jasmonate (MeJA). In contrast treatment of leaves of S. humilis with abscisic acid (ABA) and salicylic acid (SA) did not induce transcripts of either isogene. A genomic clone containing the Shpx6b gene was isolated and 594 bp of 5' sequence upstream of the translation start was fused in frame to the coding region of the uidA reporter gene and introduced into tobacco. Expression from the Shpx6b promoter in transgenic plants was determined by histochemical staining and quantitative assays of beta-glucuronidase (GUS). In transgenic tobacco, GUS expression was detected in cotyledons, vascular cells of young leaves, anthers, pollen, and the stigma and style. Wounding of the tobacco plants produced very localized GUS staining. Much more extensive staining for GUS was observed following inoculation of tobacco leaves with conidia of the fungal pathogen Cercospora nicotianae and the inoculation of wound sites with mycelium of the Oomycete pathogen Phytophthora parasitica var. nicotianae. Treatment of mature leaves with methyl jasmonate induced GUS activity while treatment with ABA, SA, and H2O2 had no effect. A similar strong induction of GUS activity was measured in young transgenic seedlings germinated on MeJA while some, but much weaker, induction of GUS activity was observed in seedlings treated with SA. The sequence of the promoter contained motifs homologous to putative cis elements in other plant genes responsive to MeJA. The Shpx6b gene is the first plant peroxidase gene shown to be induced by both microbial pathogens and MeJA and its promoter will be useful for investigations of signaling processes during fungal infection and for the expression of foreign gene products at infection sites.
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PMID:A peroxidase gene promoter induced by phytopathogens and methyl jasmonate in transgenic plants. 910 Mar 78


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