Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 plant defensin PDF1.2 has previously been shown to accumulate systemically via a salicylic acid-independent pathway in leaves of Arabidopsis upon challenge by fungal pathogens. To further investigate the signalling and transcriptional processes underlying plant defensin induction, a DNA fragment containing 1184 bp and 1232 bp upstream of the transcriptional and translational start sites, respectively, was cloned by inverse PCR. To test for promoter activity this DNA fragment was linked to the beta-glucuronidase (GUS)-encoding region of the UidA gene as a translational fusion and introduced into Arabidopsis ecotype C-24. Challenge of the transgenic plants with the fungal pathogens Alternaria brassicicola and Botrytis cinerea resulted in both local and systemic induction of the reporter gene. Wounding of the transgenic plants had no effect on GUS activity. Treatment of the transgenic plants with either jasmonates or the active oxygen generating compound paraquat strongly induced the reporter gene. In contrast, neither salicylate nor its functional analogues 2,6-dichloroisonicotinic acid and 1,2,3-benzothiodiazole-7-carbothioic acid S-methyl ester resulted in reporter gene induction. These results are consistent with the existence of a salicylic acid-independent signalling pathway, possibly involving jasmonates as regulators, that is triggered by pathogen challenge but not by wounding. The transgenic plants containing the PDF1.2-based promoter-reporter construct will provide useful tools for future genetic dissection of this novel systemic signalling pathway.
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PMID:The promoter of the plant defensin gene PDF1.2 from Arabidopsis is systemically activated by fungal pathogens and responds to methyl jasmonate but not to salicylic acid. 986 13

Screening of a genomic library from tomato plants (Lycopersicon esculentum) with a cDNA probe encoding a subtilisin-like protease (PR-P69) that is induced at the transcriptional level following pathogen attack (Tornero, P., Conejero, V., and Vera, P. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 6332-6337) resulted in the isolation of a cluster of genomic clones that comprise a tandem of four different subtilisin-like protease genes (P69A, P69B, P69C, and P69D). Sequence analyses and comparison of the encoded proteins revealed that all are closely related (79 to 88% identity), suggesting that all are derived from a common ancestral gene. mRNA expression analysis as well as studies of transgenic plants transformed with promoter-beta-glucuronidase fusions for each of these genes revealed that the four genes exhibit differential transcriptional regulation and expression patterns. P69A and P69D are expressed constitutively, but with different expression profiles during development, whereas the P69B and P69C genes show expression following infection with Pseudomonas syringae and are also up-regulated by salicylic acid. We propose that these four P69-like proteases, as members of a complex gene family of plant subtilisin-like proteases, may be involved in a number of specific proteolytic events that occur in the plant during development and/or pathogenesis.
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PMID:A genomic cluster containing four differentially regulated subtilisin-like processing protease genes is in tomato plants. 989 Oct 3

Vacuolar processing enzyme (VPE) has been shown to be responsible for maturation of various seed proteins in protein-storage vacuoles. Arabidopsis has three VPE homologues; betaVPE is specific to seeds and alphaVPE and gammaVPE are specific to vegetative organs. To investigate the activity of the vegetative VPE, we expressed the gammaVPE in a pep4 strain of the yeast Saccharomyces cerevisiae and found that gammaVPE has the ability to cleave the peptide bond at the carbonyl side of asparagine residues. An immunocytochemical analysis revealed the specific localization of the gammaVPE in the lytic vacuoles of Arabidopsis leaves that had been treated with wounding. These findings indicate that gammaVPE functions in the lytic vacuoles as the betaVPE does in the protein-storage vacuoles. The betaVPE promoter was found to direct the expression of the beta-glucuronidase reporter gene in seeds and the root tip of transgenic Arabidopsis plants. On the other hand, both the alphaVPE and gammaVPE promoters directed the expression in senescent tissues, but not in young intact tissues. The mRNA levels of both alphaVPE and gammaVPE were increased in the primary leaves during senescence in parallel with the increase of the mRNA level of a senescence-associated gene (SAG2). Treatment with wounding, ethylene and salicylic acid up-regulated the expression of alphaVPE and gammaVPE, while jasmonate slightly up-regulated the expression of gammaVPE. These gene expression patterns of the VPEs were associated with the accumulation of vacuolar proteins that are known to respond to these treatments. Taken together, the results suggest that vegetative VPE might regulate the activation of some functional proteins in the lytic vacuoles.
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PMID:Vacuolar processing enzyme is up-regulated in the lytic vacuoles of vegetative tissues during senescence and under various stressed conditions. 1041 25

Following a pathogenic attack, plants are able to mount a defense response with the coordinated activation of a battery of defense-related genes. In this study we have characterized the mode of expression of the P69B and P69C genes from tomato (Lycopersicon esculentum Mill.), which encodes two closely related subtilisin-like proteases associated with the defense response. We have compared the mode of gene regulation in heterologous transgenic Arabidopsis plants harboring promoter-beta-glucuronidase (GUS) and promoter-luciferase (LUC) gene fusions for these two genes. These studies revealed that the P69B and P69C promoters are induced by salicylic acid as well as during the course of both a compatible and an incompatible interaction with Pseudomonas syringae. Furthermore, P69B and P69C expression takes place in both the local and the distal (noninoculated) leaves upon inoculation with bacteria but following different and unique tissue-specific patterns of expression that are also different to that described for most other classical PR genes. Also, we report that luciferin, the substrate for the reporter luciferase (LUC) gene, is able to activate expression of PR genes, and this may pose a problem when using this gene reporter system in studies related to plant defense.
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PMID:Local and systemic induction of two defense-related subtilisin-like protease promoters in transgenic Arabidopsis plants. Luciferin induction of PR gene expression. 1108 Feb 82

To determine which components of the plant defense response make important contributions to limiting pathogen attack, an M(2) mutagenized population of a transgenic Arabidopsis line was screened for mutants showing constitutive expression of beta-glucuronidase activity driven by the promoter region of the CEVI-1 gene. The CEVI-1 gene originally was isolated from tomato plants and has been shown to be induced in susceptible varieties of tomato plants by virus infection in a salicylic acid-independent manner. We report here the characterization of a recessive mutant, detachment9 (dth9). This mutant is more susceptible to both virulent and avirulent forms of the oomycete Peronospora and also exhibits increased susceptibility to the moderately virulent bacterial pathogen Pseudomonas syringae pv maculicola ES4326. However, this mutant is not affected in salicylic acid metabolism and shows normal expression of pathogenesis-related (PR) genes after pathogen attack. Furthermore, after inoculation with avirulent pathogens, the dth9 mutant shows a compromised systemic acquired resistance response that cannot be complemented by exogenous application of salicylic acid, although this molecule is able to promote normal activation of PR genes. Therefore, the dth9 mutation defines a regulator of disease susceptibility that operates upstream or independently of salicylic acid. Pleiotropy is also evident in the dth9 mutant in the sense that the shoots of dth9 plants are insensitive to the exogenously applied auxin analog 2,4-dichlorophenoxyacetic acid.
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PMID:Arabidopsis dth9 mutation identifies a gene involved in regulating disease susceptibility without affecting salicylic acid-dependent responses. 1109 Feb 13

Receptor-like protein kinases (RLKs) are encoded by a divergent multigene family and their functions have been implicated in a wide range of signal transduction pathways. In this study, we examined the effect of salicylic acid (SA) on the expression of RLK genes in Arabidopsis thaliana. RNA gel blot analysis revealed that transcripts of RKC1 and a number of its homologs, whose translation products contain C-X8-C-X2-C motifs in the putative extracellular domain, accumulated to a higher level in response to SA treatment of plants. The chimeric fusion between the RKC1 5'-upstream region and the beta-glucuronidase (GUS) reporter gene reproduced the SA responsiveness in transgenic plants. In addition, some of RLK genes of the leucine-rich repeat (LRR) class and those of the S-domain class were also induced by SA. We found that the upstream regions of these SA-responsive RLK genes contain the TTGAC sequence, which has been suggested to be important for induced expression of many plant defense genes. These results suggest the involvement of a number of RLKs in SA-mediated defense responses.
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PMID:Salicylic acid induces the expression of a number of receptor-like kinase genes in Arabidopsis thaliana. 1110 Jul 76

To elucidate heterologous promoter function in gymnosperms, we introduced the bean phenylalanine ammonia-lyase-beta-glucuronidase (PAL2-GUS) gene fusion into white pine (Pinus strobus L.). Over 15 lines were produced and integration of Agrobacterium T-DNA was confirmed by Southern analysis. Induction of the reporter gene was detected in all of the lines tested following UV illumination. In contrast, a weak but constant induction was seen in only a few lines following treatment with salicylic acid (SA) or jasmonic acid (JA). However, pretreatment of suspension cultures with SA or JA enhanced the induction of PAL2-GUS expression by UV irradiation. This specific enhancement or potentiation was reduced by 50% by treating the cells with indomethacin, an inhibitor of phospholipase activity, suggesting that the observed potentiation of UV induction involves the octadecanoid pathway. The UV induction was completely abolished by treating the cells with okadaic acid, an inhibitor of phosphatase activity. Thus, the induction of the heterologous PAL2 promoter from bean is consistent with the induction of phenylalanine ammonia-lyase (PAL) in angiosperms. Furthermore, our findings suggest that conifers, although phylogenetically distant to angiosperms, share some conserved promoter elements and some signal transduction mechanisms for UV-light perception.
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PMID:Inducible expression of the heterologous PAL2 promoter from bean in white pine (Pinus strobus) transgenic cells. 1144 95

A novel Arabidopsis mutant has been identified with constitutive expression of GST1-GUS using plants with a pathogen-responsive reporter transgene containing the beta-glucuronidase (GUS) coding region driven by the GST1 promoter. The recessive mutant, called agd2 (aberrant growth and death2), has salicylic acid (SA)-dependent increased resistance to virulent and avirulent strains of the bacterial pathogen Pseudomonas syringae, elevated SA levels, a low level of spontaneous cell death, callose deposition, and enlarged cells in leaves. The enhanced resistance of agd2 to virulent P. syringae requires the SA signaling component NONEXPRESSOR OF PR1 (NPR1). However, agd2 renders the resistance response to P. syringae carrying avrRpt2 NPR1-independent. Thus agd2 affects both an SA- and NPR1-dependent general defense pathway and an SA-dependent, NPR1-independent pathway that is active during the recognition of avirulent P. syringae. agd2 plants also fail to show a hypersensitive cell death response (HR) unless NPR1 is removed. This novel function for NPR1 is also apparent in otherwise wild-type plants: npr1 mutants show a stronger HR, while NPR1-overproducing plants show a weaker HR when infected with P. syringae carrying the avrRpm1 gene. Spontaneous cell death in agd2 is partially suppressed by npr1, indicating that NPR1 can suppress or enhance cell death depending on the cellular context. agd2 plants depleted of SA show a dramatic exacerbation of the cell-growth phenotype and increased callose deposition, suggesting a role for SA in regulating growth and this cell-wall modification. AGD2 may function in cell death and/or growth control as well as the defense response, similarly to what has been described in animals for the functions of NFkappaB.
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PMID:The Arabidopsis aberrant growth and death2 mutant shows resistance to Pseudomonas syringae and reveals a role for NPR1 in suppressing hypersensitive cell death. 1153 66

Sporamin, a tuberous storage protein of sweet potato, was systemically expressed in leaves and stems by wound stimulation. In an effort to demonstrate the regulatory mechanism of wound response on the sporamin gene, a 1.25 kb sporamin promoter was isolated for studying the wound-induced signal transduction. Two wound response-like elements, a G box-like element and a GCC core-like sequence were found in this promoter. A construct containing the sporamin promoter fused to a beta-glucuronidase (GUS) gene was transferred into tobacco plants by Agrobacterium-mediated transformation. The wound-induced high level of GUS activity was observed in stems and leaves of transgenic tobacco, but not in roots. This expression pattern was similar to that of the sporamin gene in sweet potatoes. Exogenous application of methyl jasmonate (MeJA) activated the sporamin promoter in leaves and stems of sweet potato and transgenic tobacco plants. A competitive inhibitor of ethylene (2,5-norbornadiene; NBD) down-regulated the effect of MeJA on sporamin gene expression. In contrast, salicylic acid (SA), an inhibitor of the octadecanoid pathway, strongly suppressed the sporamin promoter function that was stimulated by wound and MeJA treatments. In conclusion, wound-response expression of the sporamin gene in aerial parts of plants is regulated by the octadecanoid signal pathway.
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PMID:Wound-response regulation of the sweet potato sporamin gene promoter region. 1185 24

Expression of the Sar8.2 gene family is induced by salicylic acid (SA) in tobacco during induction of systemic acquired resistance. Expression of Sar8.2b, one member of this 12-member family, was detected as early as 12 h after treatment with SA and was maximal 36 h after SA treatment. In NahG transgenic tobacco plants, benzothiadiazole and dichloroisonicotinic acid induced expression of Sar8.2b but SA did not, suggesting that expression of the Sar8.2b gene is SA-dependent. Several putative cis-acting elements were found in the Sar8.2b gene promoter region, including an as-1 element and GT-1 and Dof binding sequences. We constructed a series of progressive deletion mutations in the Sar8.2b promoter region linked to the beta-glucuronidase (GUS) coding region and analyzed GUS activities by stable expression in transformants of Arabidopsis thaliana. Deletions between -728 and -927 bp or between -351 and -197 bp of the promoter region resulted in a significant reduction in GUS activity induced by SA treatment as shown in stable transformants of A. thaliana. The -197 bp fragment of the promoter region was found to confer a relatively low level of GUS activity induced by SA treatment in stable expression of transformants in A. thaliana. The results suggest that 927 bp of the Sar8.2b gene promoter confers full promoter activity and that cis-acting elements required for high-level SA-inducible expression of the Sar8.2b gene may exist within the regions -728 to -927 bp and -197 to -351 bp.
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PMID:Cloning and identification of the promoter of the tobacco Sar8.2b gene, a gene involved in systemic acquired resistance. 1206 6


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