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)

Expression of at least two genes from bean encoding the defense-related protein chitinase has been shown previously to be transcriptionally regulated by the phytohormone ethylene. We have determined the complete nucleotide sequence of one of these genes, the CH5B gene, which resides on a 4.7-kilobase fragment of bean genomic DNA. The structural gene consists of a single open reading frame and encodes the 301 amino acids of the mature protein and a 26-amino acid signal peptide. The CH5B gene has been introduced into tobacco plants using Agrobacterium Ti-plasmid vectors. Little or no expression of the bean gene was observed when transgenic tobacco plants were grown in air; however, exposure of these plants to an atmosphere containing 50 parts per million ethylene resulted in an approximately 20-fold to 50-fold increase in the level of the bean chitinase mRNA. Ethylene-dependent expression of a chimeric gene consisting of 1.6 kilobases of 5'-flanking DNA derived from the CH5B gene fused to the coding sequence of beta-glucuronidase indicates that this region of the CH5B gene is sufficient for ethylene-regulated expression. Deletion analysis of the CH5B promoter region has allowed us to localize these DNA sequences to within a 228-base pair region situated between -422 and -195 upstream of the transcriptional start site. This region is characterized by two short DNA sequences that are exactly conserved in a second ethylene-regulated bean chitinase gene.
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PMID:Functional analysis of DNA sequences responsible for ethylene regulation of a bean chitinase gene in transgenic tobacco. 253 12

Infection of tobacco by tobacco mosaic virus (TMV) induces coordinate expression of genes encoding acidic and basic beta-1,3-glucanase isoforms. These genes are differentially expressed in response to other treatments. Salicylate treatment induces acidic glucanase mRNA to a higher level than basic glucanase mRNA. Ethylene treatment and wounding strongly induce the basic glucanase genes but have little effect on genes encoding the acidic isoforms. Furthermore, the basic glucanase genes are constitutively expressed in roots and lower leaves of healthy plants, whereas the acidic glucanase genes are not. In order to investigate how these expression patterns are established, we fused promoter regions of an acidic and a basic glucanase gene to the beta-glucuronidase (GUS) reporter gene and examined expression of these constructs in transgenic tobacco plants. A fragment of 1750 bp and two 5'-truncated fragments of 650 bp and 300 bp of the acidic glucanase promoter were tested for induction of GUS gene expression after salicylate treatment and TMV infection. Upstream sequences of 1750 bp and 650 bp were sufficient for induction of the reporter gene by salicylate treatment and TMV infection, but the activity of the 300 bp fragment was strongly reduced. The results suggest that the 1750 bp upstream sequence of the acidic glucanase gene contains multiple regulatory elements. For the basic glucanase promoter it is shown that 1476 bp of upstream sequences were able to drive expression in response to TMV infection and ethylene treatment, but no response was found to incision wounding. Furthermore, high GUS activity was found in lower leaves and roots of healthy transgenic plants, carrying the 1476 bp basic glucanase promoter/GUS construct. When the promoter was truncated up to position -446 all activity was lost, indicating that the region between -1476 and -446 of the basic glucanase promoter is necessary for organ-specific and developmentally regulated expression as well as for induced expression in response to infection and other stress treatments.
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PMID:Analysis of regulatory elements involved in stress-induced and organ-specific expression of tobacco acidic and basic beta-1,3-glucanase genes. 844 40

The gene encoding the antifungal protein osmotin is induced by several hormonal and environmental signals. In this study, tissue-specific and inducer-mediated expression of the reporter gene beta-glucuronidase (uidA) fused to different fragment lengths of the osmotin promoter was evaluated in transgenic tobacco (Nicotiana tabacum). The region of the promoter between -248 to -108 (Fragment A) was found to be essential and sufficient for inducer (abscisic acid (ABA), C2H4 and NaCl)-mediated expression of the reporter gene. Expression of the reporter gene was developmentally regulated and increased with maturity of leaves, stem and flowers. Expression also was tissue-specific being most highly expressed in epidermis and vascular parenchyma of the stem. The regulators ABA, C2H4 and NaCl exhibited tissue-specific induction of this promoter. The promoter was specifically responsive to C2H4 in flowers at virtually all stages of development, but not responsive in these tissues to ABA or NaCl. Conversely, ABA and NaCl were able to induce reporter gene activity using promoter Fragment A in specific tissues of root where C2H4 was unable to induce activity. Further dissection of the promoter Fragment A into fragments containing either the conserved GCC element (PR); PR/AT; or G/AT sequences, and subsequent testing of these fragments fused to GUS in transgenic plants was performed. These experiments revealed that the promoter fragment containing PR element alone, although required, was barely able to allow responsiveness to C2H4. However, significant C2H4-induced activity was obtained with a promoter fragment containing the AT and PR elements together.
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PMID:Tissue-specific activation of the osmotin gene by ABA, C2H4 and NaCl involves the same promoter region. 922 51

During leaf abscission in oilseed rape (Brassica napus), cell wall degradation is brought about by the action of several hydrolytic enzymes. One of these is thought to be polygalacturonase (PG). Degenerate primers were used to isolate a PG cDNA fragment by reverse transcriptase-polymerase chain reaction from RNA extracted from ethylene-promoted leaf abscission zones (AZs), and in turn a full-length clone (CAW471) from an oilseed rape AZ cDNA library. The highest homology of this cDNA (82%) was to an Arabidopsis sequence that was predicted to encode a PG protein. Analysis of expression revealed that CAW471 mRNA accumulated in the AZ of leaves and reached a peak 24 h after ethylene treatment. Ethylene-promoted leaf abscission in oilseed rape was not apparent until 42 h after exposure to the gas, reaching 50% at 48 h and 100% by 56 h. In floral organ abscission, expression of CAW471 correlated with cell separation. Genomic libraries from oilseed rape and Arabidopsis were screened with CAW471 and the respective genomic clones PGAZBRAN and PGAZAT isolated. Characterization of these PG genes revealed that they had substantial homology within both the coding regions and in the 5'-upstream sequences. Fusion of a 1,476-bp 5'-upstream sequence of PGAZAT to beta-glucuronidase or green fluorescent protein and transformation of Arabidopsis revealed that this fragment was sufficient to drive expression of these reporter genes in the AZs at the base of the anther filaments, petals, and sepals.
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PMID:Temporal and spatial expression of a polygalacturonase during leaf and flower abscission in oilseed rape and Arabidopsis. 1184 57

We show that above a certain threshold concentration, ozone leads to leaf injury in tomato (Lycopersicon esculentum). Ozone-induced leaf damage was preceded by a rapid increase in 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity, ACC content, and ethylene emission. Changes in mRNA levels of specific ACC synthase, ACC oxidase, and ethylene receptor genes occurred within 1 to 5 h. Expression of the genes encoding components of ethylene biosynthesis and perception, and biochemistry of ethylene synthesis suggested that ozone-induced ethylene synthesis in tomato is under biphasic control. In transgenic plants containing an LE-ACO1 promoter-beta-glucuronidase fusion construct, beta-glucuronidase activity increased rapidly at the beginning of the O(3) exposure and had a spatial distribution resembling the pattern of extracellular H(2)O(2) production at 7 h, which coincided with the cell death pattern after 24 h. Ethylene synthesis and perception were required for active H(2)O(2) production and cell death resulting in visible tissue damage. The results demonstrate a selective ozone response of ethylene biosynthetic genes and suggest a role for ethylene, in combination with the burst of H(2)O(2) production, in regulating the spread of cell death.
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PMID:Ethylene synthesis regulated by biphasic induction of 1-aminocyclopropane-1-carboxylic acid synthase and 1-aminocyclopropane-1-carboxylic acid oxidase genes is required for hydrogen peroxide accumulation and cell death in ozone-exposed tomato. 1248 Oct 74

Ethylene responsive factors (ERFs) are important in regulating plant pathogen resistance, abiotic stress tolerance and plant development. Recent studies have greatly enlarged the ERF protein family and revealed more important roles of ERFs in plants. Here, we report our finding of a tomato ERF protein TSRF1, which is transcriptionally up-regulated by ethylene, salicylic acid, or Ralstonia solanacearum strain BJ1057 infection. Biochemical analysis indicates that TSRF1 specifically interacts in vitro with the GCC box, an element present in the promoters of many pathogenesis-related (PR) genes. Further investigation evidences that TSRF1 activates in vivo the expression of reporter beta-glucuronidase gene controlled by GCC box. More importantly, overexpressing TSRF1 in tobacco and tomato constitutively activates the expression of PR genes, and subsequently enhancing transgenic plant resistance to the bacterial wilt caused by Ralstonia solanacearum strain BJ1057. Therefore our investigation not only extends the functions of ERF proteins in plant resistance to R. solanacearum, but also provides further clues to understanding the mechanism of host regulatory proteins in response to the infection of pathogens.
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PMID:Tomato stress-responsive factor TSRF1 interacts with ethylene responsive element GCC box and regulates pathogen resistance to Ralstonia solanacearum. 1560 19

The transcriptional regulation of a win2-beta-glucuronidase gene fusion in transgenic potato (Solanum tuberosum) plants by wounding and ethylene has been analyzed. In common with other genes that are expressed in response to mechanical or chemical stress, win2 is transcribed at the site of injury and also in distant undamaged parts of the wounded plant. Similar kinetics of induction and patterns of transcription were observed in response to mechanical, wounding, elicitor, or arachidonic acid application. Experiments involving the use of chemicals that inhibited ethylene action, and those that increased ethylene production, showed that local induction of win2 transcription did not have an absolute requirement for ethylene, but ethylene was necessary for high levels of expression. In contrast, systemic expression of win2 required both a putative wound signal and ethylene. Ethylene alone had no direct effect on win2 gene expression in the absence of wounding.
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PMID:Ethylene and a Wound Signal Modulate Local and Systemic Transcription of win2 Genes in Transgenic Potato Plants. 1666 79

Ethylene is an important plant growth regulator perceived by membrane-bound ethylene receptors. The ETR1 ethylene receptor is positively regulated by a predicted membrane protein, RTE1, based on genetic studies in Arabidopsis. RTE1 homologs exist in plants, animals and protists, but the molecular function of RTE1 is unknown. Here, we examine RTE1 expression and subcellular protein localization in order to gain a better understanding of RTE1 and its function in relation to ETR1. Arabidopsis plants transformed with the RTE1 promoter fused to the beta-glucuronidase (GUS) reporter gene revealed that RTE1 expression partly correlates with previously described sites of ETR1 expression or sites of ethylene response, such as the seedling root, root hairs and apical hook. RTE1 transcript levels are also enhanced by ethylene treatment, and reduced by the inhibition of ethylene signaling. For subcellular localization of RTE1, a functional RTE1 fusion to red fluorescent protein (RFP) was expressed under the control of the native RTE1 promoter. Using fluorescence microscopy, RTE1 was observed primarily at the Golgi apparatus and partially at the endoplasmic reticulum (ER) in stably transformed Arabidopsis protoplasts, roots and root hairs. Next, a functional ETR1 fusion to a 5xMyc epitope tag was expressed under the control of the native ETR1 promoter. Immunohistochemistry of root hairs not only showed ETR1 residing at the ER as previously reported, but revealed substantial localization of ETR1 at the Golgi apparatus. Lastly, we demonstrated the subcellular co-localization of RTE1 and ETR1. These findings support and enhance the genetic model that RTE1 plays a role in regulating ETR1.
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PMID:Subcellular co-localization of Arabidopsis RTE1 and ETR1 supports a regulatory role for RTE1 in ETR1 ethylene signaling. 1799 43

Despite the fact that roots are the organs most subject to microbial interactions, very little is known about the response of roots to microbe-associated molecular patterns (MAMPs). By monitoring transcriptional activation of beta-glucuronidase reporters and MAMP-elicited callose deposition, we show that three MAMPs, the flagellar peptide Flg22, peptidoglycan, and chitin, trigger a strong tissue-specific response in Arabidopsis thaliana roots, either at the elongation zone for Flg22 and peptidoglycan or in the mature parts of the roots for chitin. Ethylene signaling, the 4-methoxy-indole-3-ylmethylglucosinolate biosynthetic pathway, and the PEN2 myrosinase, but not salicylic acid or jasmonic acid signaling, play major roles in this MAMP response. We also show that Flg22 induces the cytochrome P450 CYP71A12-dependent exudation of the phytoalexin camalexin by Arabidopsis roots. The phytotoxin coronatine, an Ile-jasmonic acid mimic produced by Pseudomonas syringae pathovars, suppresses MAMP-activated responses in the roots. This suppression requires the E3 ubiquitin ligase COI1 as well as the transcription factor JIN1/MYC2 but does not rely on salicylic acid-jasmonic acid antagonism. These experiments demonstrate the presence of highly orchestrated and tissue-specific MAMP responses in roots and potential pathogen-encoded mechanisms to block these MAMP-elicited signaling pathways.
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PMID:Innate immune responses activated in Arabidopsis roots by microbe-associated molecular patterns. 2034 32