Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

TEL-AML1 fusion resulting from the t(12;21)(p13;q22) is one of the most common genetic abnormalities in childhood acute lymphoblastic leukemia. Recent findings that site-specific cleavage of the MLL gene can be induced by chemotherapeutic agents such as topoisomerase-II inhibitors suggest that apoptogenic agents can cause chromosomal translocations in hematopoietic cells. This study demonstrates a possible relationship between exposure to apoptogenic stimuli, TEL breaks, and the formation of TEL-AML1 fusion in immature B lymphocytes. Short-term culture of immature B cell lines in the presence of apoptogenic stimuli such as serum starvation, etoposide, or salicylic acid induced double-strand breaks (DSBs) in intron 5 of the TEL gene and intron 1 of the AML1 gene. TEL-AML1 fusion transcripts were also identified by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in cell lines treated by serum starvation or aminophylline. DSBs within the TEL gene were also associated with fusion to other unknown genes, presumably as a result of chromosomal translocation. We also examined 67 cord blood and 147 normal peripheral blood samples for the existence of in-frame TEL-AML1 fusion transcripts. One cord blood sample (1.5%) and 13 normal peripheral blood samples (8.8%) were positive as detected by nested RT-PCR. These data suggest that breakage and fusion of TEL and AML1 may be relatively common events and that sublethal apoptotic signals could play a role in initiating leukemogenesis via the promotion of DNA damage.
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PMID:Breakage and fusion of the TEL (ETV6) gene in immature B lymphocytes induced by apoptogenic signals. 1115 92

Mutants of Pseudomonas fluorescens WCS374 defective in biosynthesis of the fluorescent siderophore pseudobactin still display siderophore activity, indicating the production of a second siderophore. A recombinant cosmid clone (pMB374-07) of a WCS374 gene library harboring loci necessary for the biosynthesis of salicylic acid (SA) and this second siderophore pseudomonine was isolated. The salicylate biosynthesis region of WCS374 was localized in a 5-kb EcoRI fragment of pMB374-07. The SA and pseudomonine biosynthesis region was identified by transfer of cosmid pMB374-07 to a pseudobactin-deficient strain of P. putida. Sequence analysis of the 5-kb subclone revealed the presence of four open reading frames (ORFs). Products of two ORFs (pmsC and pmsB) showed homologies with chorismate-utilizing enzymes; a third ORF (pmsE) encoded a protein with strong similarity with enzymes involved in the biosynthesis of siderophores in other bacterial species. The region also contained a putative histidine decarboxylase gene (pmsA). A putative promoter region and two predicted iron boxes were localized upstream of pmsC. We determined by reverse transcriptase-mediated PCR that the pmsCEAB genes are cotranscribed and that expression is iron regulated. In vivo expression of SA genes was achieved in P. putida and Escherichia coli cells. In E. coli, deletions affecting the first ORF (pmsC) diminished SA production, whereas deletion of pmsB abolished it completely. The pmsB gene induced low levels of SA production in E. coli when expressed under control of the lacZ promoter. Several lines of evidence indicate that SA and pseudomonine biosynthesis are related. Moreover, we isolated a Tn5 mutant (374-05) that is simultaneously impaired in SA and pseudomonine production.
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PMID:Analysis of the pmsCEAB gene cluster involved in biosynthesis of salicylic acid and the siderophore pseudomonine in the biocontrol strain Pseudomonas fluorescens WCS374. 1122 88

Transcriptionally active Ty1-copia LTR-retrotransposons were found in oat using RT-PCR for amplifying the reverse transcriptase domain. Sequence analysis of the RT-PCR clones suggested that oat LTR-retrotransposons consist of at least seven groups, which were tentatively designated as Oatrt1 to Oatrt7. A full length copy of Oatrt1 was isolated from an oat genomic library, and was designated OARE-1. OARE-1 was 8,665 bp long and a member of the BARE-1 subgroup. The oat genome carried it in multiple copies (at least 10,000 copies / a hexaploid genome). The expression of OARE-1 was intensively induced by wounding, UV light, jasmonic acid and salicylic acid, and its pattern was very similar to that of the PAL (phenylalanin ammonia lyase) gene. Furthermore, OARE-1 was highly activated by infection with an incompatible race of the crown rust fungus, Puccinia coronata. These results suggest that OARE-1 is highly sensitive to various abiotic and biotic stimuli leading to plant defense responses.
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PMID:OARE-1, a Ty1-copia retrotransposon in oat activated by abiotic and biotic stresses. 1177 27

Drought treatment induces the accumulation of dcTLP, which is similar in structure to the thaumatin-like proteins (TLPs) found in the embryogenic calli, seedlings, and mature plants of carrot (Daucus carota). We isolated a full-length dcTLP cDNA clone from carrot and characterized the 5' upstream sequences. The coding region of dcTLP consisted of 645 nucleotides; the theoretical pI value was 4.9, and its molecular weight was approximately 22 kDa. The production of dcTLP transcripts in the seedlings increased dramatically with dehydration treatment but was not affected by abscisic acid (ABA), salicylic acid, or jasmonic acid. The expression patterns of dcTLP mRNA at different developmental stages and in response to a variety of signal molecules was analyzed using reverse transcriptase-PCR and promoter analysis with fused genes of 0.5-kb 5' upstream sequences in which beta-glucuronidase (GUS) reporter genes (gus) were established. The induction of dcTLP was found to be highly specific to drought stress in the embryogenic calli, seedlings, and mature plants. Our results suggest that this new isoform of TLP that has been isolated from carrot is a drought-specific, ABA-independent, non-organ-specific, and non-developmental-stage-specific protein.
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PMID:Drought-inducible-but ABA-independent-thaumatin-like protein from carrot (Daucus carota L.). 1578 5

Capsaicin, a pungency factor alkaloid of Capsicum fruits, is biosynthesized by enzymatic condensation of vanillylamine, a phenyl propanoid intermediate, and 8-methyl-nonenoic acid, a fatty acid derivative from the leucine/valine pathway by capsaicin synthase. Biotic elicitors, such as aqueous mycelial extracts of Rhizopus oligosporus and Aspergillus niger, and abiotic elicitors, such as salicylic acid and methyl jasmonate, were incorporated to cell-suspension cultures of Capsicum frutescens. The maximum elicitation of capsaicinoids to the extent of 6-folds was noticed when mycelial extracts of R. oligosporus were incorporated to cell-suspension cultures. The phenyl propanoid intermediates were elicited to the extent of 3-4-fold, whereas the levels of 8-methyl-nonanoic acid increased 6-fold in R. oligosporus mycelial-extract-treated cultures. The enzymatic assays of caffeic acid O-methyl transferases, keto acyl synthase, and capsaicin synthase were performed in elicited and nonelicited cell-suspension cultures. These enzymes were overexpressed in R. oligosporus mycelial-extract-treated suspension cultures, which was also confirmed by reverse transcriptase polymerase chain reaction studies. This is the first paper on the overexpression of 8-methyl-nonanoic acid leading to capsaicin biosynthesis using elicitors.
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PMID:Valine pathway is more crucial than phenyl propanoid pathway in regulating capsaicin biosynthesis in Capsicum frutescens mill. 1693 24

Non-nucleoside inhibitors of HIV reverse transcriptase (NNRTIs), albeit not the mainstays of HIV/AIDS treatment, have become increasingly important in highly active antiretroviral therapy (HAART) due to their unique mechanism of action. Several years ago our group identified the alkenyldiarylmethanes (ADAMs) as a potent and novel class of NNRTIs; however, the most active compounds were found to be metabolically unstable. Subsequent work has led to the synthesis of 33 analogues, with improved metabolic profiles, through the replacement of labile esters with various heterocycles, nitriles, and thioesters. As a result, a number of hydrolytically stable NNRTIs were identified with anti-HIV activity in the nanomolar concentration range. Furthermore, an improved pharmacophore model has been developed based on the new ADAM series, in which a salicylic acid-derived aryl ring is oriented cis to the side chain and the aryl ring that is trans to the side chain contains a hydrogen bond acceptor site within the plane of the ring.
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PMID:Synthesis and biological evaluation of alkenyldiarylmethane HIV-1 non-nucleoside reverse transcriptase inhibitors that possess increased hydrolytic stability. 1780 90

We report the identification of novel defence genes in canola by using a cDNA microarray from Arabidopsis. We examined changes that occur in the abundance of transcripts corresponding to 2375 Arabidopsis expressed sequence tags (selected for defence gene identification) following inoculation of canola plants with the fungal necrotrophic leaf pathogen, Alternaria brassicicola. Microarray data obtained from this cross-hybridisation experiment were compared to expression profiles previously obtained from the equivalent Arabidopsis experiment. Homology searches using a canola expressed sequence tag database with approximately 6000 unique clones led to identification of canola defence genes. Pathogen-responsive transcripts included those associated to known defence genes, reactive oxygen species metabolism, disease resistance and regulatory genes, and cell maintenance/metabolism genes. Using specific primers for quantitative real-time reverse transcriptase PCR, gene expression profiles in canola were obtained that demonstrated coordinated defence responses, including systemic responses in distal tissue and salicylic acid- and methyl jasmonate-mediated signalling against A. brassicicola.
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PMID:Identification of plant defence genes in canola using Arabidopsis cDNA microarrays. 1876 93

Plant root-associated bacteria (rhizobacteria) elicit plant basal immunity referred to as induced systemic resistance (ISR) against multiple pathogens. Among multi-bacterial determinants involving such ISR, the induction of ISR and promotion of growth by bacterial volatile compounds was previously reported. To exploit global de novo expression of plant proteins by bacterial volatiles, proteomic analysis was performed after exposure of Arabidopsis plants to the rhizobacterium Bacillus subtilis GB03. Ethylene biosynthesis enzymes were significantly up-regulated. Analysis by quantitative reverse transcriptase polymerase chain reaction confirmed that ethylene biosynthesis-related genes SAM-2, ACS4, ACS12, and ACO2 as well as ethylene response genes, ERF1, GST2, and CHIB were up-regulated by the exposure to bacterial volatiles. More interestingly, the emission of bacterial volatiles significantly up-regulated both key defense mechanisms mediated by jasmonic acid and salicylic acid signaling pathways. In addition, high accumulation of antioxidant proteins also provided evidence of decreased sensitivity to reactive oxygen species during the elicitation of ISR by bacterial volatiles. The present results suggest that the proteomic analysis of plant defense responses in bacterial volatile-mediated ISR can reveal the mechanisms of plant basal defenses orchestrated by endogenous ethylene production pathways and the generation of reactive oxygen species.
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PMID:Proteome analysis of Arabidopsis seedlings exposed to bacterial volatiles. 2082 Aug 2

The plant-specific NAC (NAM, ATAF, and CUC) transcription factor family plays a vital role in various plant growth and developmental processes as well as in stress resistance. Using RNA sequencing, we found that the ClNAC genes (ClNAC1-44) were the most strongly up-regulated transcription factor family in Chrysanthemum lavandulifolium leaves under salt treatment. We carried out reverse transcriptase polymerase chain reaction to monitor ClNAC genes response against multiple stresses and hormonal treatments including salt, drought, cold, heat, abscisic acid and salicylic acid treatments. The results showed that 35 ClNAC genes were differentially expressed in different organ, and 32 ClNAC genes could respond to at least 2 kinds of treatments. Quantitative real time polymerase chain reaction showed that 10 ClNAC genes belonging to 7 different subfamilies could respond to at least 5 kinds of treatments. Over 50-fold variation in transcriptional levels of ClNAC17 and ClNAC21 genes was observed under 6 different types of treatments. In the present study, high-level expression of ClNAC genes under abiotic stresses and hormonal treatments suggests that the NAC transcription factors play important roles in abiotic stress tolerance and adaptation.
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PMID:Transcriptome-wide survey and expression analysis of stress-responsive NAC genes in Chrysanthemum lavandulifolium. 2279 15


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