Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report on the interactions of alfalfa with Xanthomonas campestris pv. alfalfae and Pseudomonas syringae pv. pisi. A hypersensitive response was observed when leaves were infiltrated with P. s. pv. pisi, which remained strictly limited to the injected zone. The compatible interaction with X. c. pv. alfalfae was characterized by water-soaking symptoms and the spreading of the bacterium into the leaf blade. Analyses of transcript accumulation were conducted with cDNAs encoding enzymes involved in phytoalexin synthesis: chalcone synthase (CHS), chalcone isomerase (CHI), and isoflavone reductase (IFR). In incompatible interactions the maximum accumulation of the CHS, CHI, and IFR transcripts was observed 6 hr postinfection. In the compatible interaction, the induction of these transcripts was delayed until 25-30 hr postinfection, and the level of their accumulation was considerably lower. Extending this molecular analysis to the root system showed that the reaction of roots during an incompatible interaction was quite comparable to that of leaves. To complete these analyses, expression of genes encoding pathogenesis-related (PR) proteins in leaves was also analyzed by polymerase chain reaction. High-level accumulation of a 0.8-kb transcript encoding a PR protein was observed 6 to 30 hr postinfection in the incompatible interaction.
Mol Plant Microbe Interact
PMID:Pathological and molecular characterizations of alfalfa interactions with compatible and incompatible bacteria, Xanthomonas campestris pv. alfalfae and Pseudomonas syringae pv. pisi. 827 75

Nuclear transcript run-on analysis was used to investigate++ the relative transcription rates of genes encoding enzymes of isoflavonoid phytoalexin biosynthesis and related pathways in elicitor-treated alfalfa (Medicago sativa L.) cell suspension cultures. Genes encoding L-phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and chalcone reductase (CHR) were most rapidly activated, with increases in transcription measurable within 10-20 min after elicitation. Cinnamic acid 4-hydroxylase (C4H), chalcone isomerase (CHI), isoflavone reductase (IFR) and caffeic acid 3-0-methyltransferase (COMT) genes were also rapidly activated, but at a slower initial rate. Transcription of chalcone 2'-O-methyltransferase (CHOMT), and 1,3-beta-D-glucanase genes was less rapid, with lag periods of 60 and 30 min post-elicitation, respectively. Treatment of cells with a PAL inhibitor L-alpha-aminooxy-beta-phenylpropionic acid (AOPP) resulted in increased transcription of PAL, CHS and CHR, but reduced transcription of CHOMT, indicating a role for phenylpropanoid products as both negative and positive regulators of gene expression within the phenylpropanoid pathway.
Plant Mol Biol 1996 Feb
PMID:Stress responses in alfalfa (Medicago sativa L.). XX. Transcriptional activation of phenlpropanoid pathway genes in elicitor-induced cell suspension cultures. 860 96

The phytopathogenic fungus Nectria haematococca detoxifies pisatin, a phytoalexin produced by pea. Pisatin demethylating ability (a phenotype called Pda) is due to pisatin demethylase (pdm) and the genes encoding this enzyme are called PDA. Some isolates rapidly acquire a high to moderate rate of pisatin demethylating activity culture in response to pisatin (phenotypes PdaSH and PdaSM), while other isolates only slowly demethylate pisatin (phenotype PdaLL). Here we report that PDA-specific RNA levels increased more quickly in response to pisatin in isolates with PDA genes confering a PdaSH or PdaSM phenotype than in isolates with gene conferring a PdaLL phenotype. In addition, the pdm activity of transformants of N. haematococca containing chimeric constructs of PDASH and PDALL genes in which the 5' regulatory regions of these genes had been switched supports the conclusion that differential expression of PDA genes is responsible for the different Pda phenotypes detected in vitro. Northern analysis of pea tissue infected with isolates carrying PDASH or PDALL genes indicated that differential induction of these genes also occurred in planta. Only PDASH-specific RNA is readily detected in tissue infected with isolates containing PDASH and PDALL genes. Recently a pisatin biosynthetic gene, isoflavone reductase (IFR), has been identified. Using the polymerase chain reaction, qualitative detection of IFR and PDASH transcripts in infected tissue were made to assess the relative timing of these genes' expression. No transcripts were detected 6 h after inoculation, but transcripts of both genes were detected a 12 h, suggesting an interplay between the regulatory systems controlling the plants's defense response and the pathogen's counter response.
Mol Plant Microbe Interact 1996 Aug
PMID:Expression of the pisatin detoxifying genes (PDA) of Nectria haematococca in vitro and in planta. 875 24

Exposure of harvested grapefruit to UV-C (254 nm) irradiation was previously found to induce resistance against the green mold decay caused by Penicillium digitatum. In order to gain insight into the mechanism of this UV-induced resistance we initiated a study for isolation of genes induced during this process. Using the differential display method we cloned cDNA representing an mRNA which is accumulated in grapefruit peel upon UV irradiation. Sequence analysis revealed that this cDNA represents a gene encoding for an isoflavone reductase-like protein and was termed IRL (isoflavone reductase-like). The grapefruit IRL protein sequence has high homology also to a novel family of other isoflavone reductase-like proteins present in few non-legume plants and whose function is not clear yet. The UV dose, and time following it, which lead to maximal accumulation of the IRL transcript were found to be similar to those leading to maximal induced resistance. The expression of the IRL gene was demonstrated to be induced also by wounding and pathogen infection.
Plant Mol Biol 1998 Apr
PMID:The expression of a grapefruit gene encoding an isoflavone reductase-like protein is induced in response to UV irradiation. 952 Feb 76

Cadmium is a toxic heavy metal with no known biological activity. Differential display of mRNA was employed to isolate cDNA corresponding to the transcript that is induced in cadmium-treated Candida sp. In this report we describe the molecular characterization of the CIP1 gene, which was shown to be rapidly induced after cadmium treatment. Northern blot analysis showed that the CIP1 transcript was not present in normal cells, but accumulated at higher levels in cadmium-treated cells. Treatment of other heavy metals such as copper, mercury, lead, zinc, or heat-shock had no effect on the expression of the CIP1 gene. Sequence analysis of CIP1 revealed that it encodes a 32 kDa hydrophobic protein that contains a putative transmembrane domain. The deduced amino acid sequence of CIP1 showed a little homology with isoflavone reductase of plants. From the promoter sequence analysis, we also identified a sequence similar to pas, a cadmium-responsive element of the ParA gene in tobacco. Our results suggest that Candida CIP1 may play a crucial role in the establishment of specific cellular response to stress evolved by the cadmium treatment.
Mol Cells 1998 Feb 28
PMID:Expression of the CIP1 gene induced under cadmium stress in Candida sp. 957 36

Alfalfa (Medicago sativa) varieties with antibiosis-based resistance to the root-lesion nematode (Pratylenchus penetrans), a migratory endoparasite of many crops, have been developed by recurrent selection. Individual plants from these varieties that support significantly lower nematode reproduction were identified for molecular and biochemical characterization of defense responses. Before nematode infection, RNA blot analysis revealed 1.3-1.8-fold higher phenylpropanoid pathway mRNA levels in roots of three resistant plants as compared to three susceptible alfalfa plants. The mRNAs encoded the first enzyme in the pathway (phenylalanine ammonia-lyase), the first in the pathway branch for flavonoid biosynthesis (chalcone synthase), a key enzyme in medicarpin biosynthesis (isoflavone reductase) and a key enzyme in the pathway branch for biosynthesis of lignin cell wall precursors (caffeic acid O-methyltransferase). After nematode infection, the mRNAs declined over 48 h in resistant roots but rose in susceptible plants during the first 12 h after-infection and then declined. Acidic beta-1,3-glucanase mRNA levels were initially similar in both root types but accumulated more rapidly in resistant than in susceptible roots after nematode infection. Levels of a class I chitinase mRNA were similar in both root types. Histone H3.2 mRNA levels, initially 1.3-fold higher in resistant roots, declined over 6-12 h to levels found in susceptible roots and remained stable in both root types thereafter. Defense-response gene transcripts in roots of nematode-resistant and susceptible alfalfa plants thus differed both constitutively and in inductive responses to nematode infection. HPLC analysis of isoflavonoid-derived metabolites of the phenylpropanoid pathway revealed similar total constitutive levels, but varying relative proportions and types, in roots of the resistant and susceptible plants. Nematode infection had no effect on isoflavonoid levels. Constitutive levels of the phytoalexin medicarpin were highest in roots of the two most resistant plants. Medicarpin inhibited motility of P. penetrans in vitro.
Plant Mol Biol 1998 Dec
PMID:Alfalfa (Medicago sativa L.) resistance to the root-lesion nematode, Pratylenchus penetrans: defense-response gene mRNA and isoflavonoid phytoalexin levels in roots. 986 6

Plants contain a large number of proteins homologous to isoflavone reductase, an NADPH-dependent reductase involved in the biosynthesis of isoflavonoid phytoalexins in legumes. Although some are bonafide isoflavone reductases, others may catalyze distinct reductase reactions. Two tobacco genes, TP7 and A622, encoding isoflavone reductase-like proteins, had been previously identified from their unique expression patterns, but their functions were not known. We show here that TP7 is a tobacco phenylcoumaran benzylic ether reductase involved in lignan biosynthesis, but that A622 is not. To gain insight into the possible function of A622, we analyzed in detail the expression patterns of the A622 gene by RNA and protein blots, immunohistochemistry, and its promoter expression in transgenic Nicotiana sylvestris roots. The A622 expression patterns were qualitatively similar to those of putrescine N-methyltransferase, the first enzyme in nicotine biosynthesis, suggesting that A622 may function in the metabolism of nicotine or related alkaloids.
Plant Mol Biol 2002 Oct
PMID:Expression patterns of two tobacco isoflavone reductase-like genes and their possible roles in secondary metabolism in tobacco. 1236 19

We have isolated and characterized a rice isoflavone reductase-like gene, OsIRL, whose expression is induced by a fungal elicitor. The OsIRL cDNA contains 1203 bp with an open reading frame of 942 nucleotides encoding 314 amino acids. The deduced amino acid sequence of OsIRL has a putative pyridine nucleotide binding domain and is 68% homologous with the maize isoflavone reductase-like gene. Southern blot analysis revealed that OsIRL belongs to a small multigene family. Expression of OsIRL was induced by treatment with a fungal elicitor and jasmonic acid as well as by inoculation with rice blast fungus. Cycloheximide (1 microM), strongly inhibited the induction of OsIRL by the fungal elicitor, indicating that new protein synthesis is required. The protein kinase inhibitor, staurosporine (1 microM), had little effect, but the phosphatase inhibitor, calyculin A (1 microM), strongly inhibited induction. Treatment with salicylic acid (SA, 5 mM) strongly inhibited expression of OsIRL in response to fungal elicitor and JA, while abscisic acid (ABA, 200 microM) also strongly antagonized OsIRL induction by JA, but had only a weak effect on induction by the fungal elicitor. These results suggest that the expression of OsIRL is positively regulated by phytohormones such as JA, and negatively by phytohormones such as SA, ABA.
Mol Cells 2003 Oct 31
PMID:A rice isoflavone reductase-like gene, OsIRL, is induced by rice blast fungal elicitor. 1465 Dec 65

Pisatin is an isoflavonoid phytoalexin synthesized by pea (Pisum sativum L.). Previous studies have identified two enzymes apparently involved in the synthesis of this phytoalexin, isoflavone reductase (IFR), which catalyzes an intermediate step in pisatin biosynthesis, and (+)6a-hydroxymaackiain 3-O-methyltransferase (HMM), an enzyme catalyzing the terminal step. To further evaluate the involvement of these enzymes in pisatin biosynthesis, sense- and antisense-oriented cDNAs of Ifr and Hmm fused to the 35s CaMV promoter, and Agrobacterium rhizogenes, were used to produce transgenic pea hairy root cultures. PDA, a gene encoding pisatin demethylating activity (pda) in the pea-pathogenic fungus Nectria haematococca, also was used in an attempt to reduce pisatin levels. Although hairy root tissue with either sense or antisense Ifr cDNA produced less pisatin, the greatest reduction occurred with sense or antisense Hmm cDNA. The reduced pisatin production in these lines was associated with reduced amounts of Hmm transcripts, HMM protein, and HMM enzyme activity. Hairy roots containing the PDA gene also produced less pisatin. To evaluate the role of pisatin in disease resistance, the virulence of N. haematococca on the transgenic roots that produced the lowest levels of pisatin was tested. Hairy roots expressing antisense Hmm were more susceptible than the control hairy roots to isolates of N. haematococca that are either virulent or nonvirulent on wild-type pea plants. This appears to be the first case of producing transgenic plant tissue with a reduced ability to produce a phytoalexin and demonstrating that such tissue is less resistant to fungal infection: these results support the hypothesis that phytoalexin production is a disease resistance mechanism.
Mol Plant Microbe Interact 2004 Jul
PMID:Introduction of plant and fungal genes into pea (Pisum sativum L.) hairy roots reduces their ability to produce pisatin and affects their response to a fungal pathogen. 1524 74

As part of a genomics strategy to characterize inducible defences against insect herbivory in poplar, we developed a comprehensive suite of functional genomics resources including cDNA libraries, expressed sequence tags (ESTs) and a cDNA microarray platform. These resources are designed to complement the existing poplar genome sequence and poplar (Populus spp.) ESTs by focusing on herbivore- and elicitor-treated tissues and incorporating normalization methods to capture rare transcripts. From a set of 15 standard, normalized or full-length cDNA libraries, we generated 139,007 3'- or 5'-end sequenced ESTs, representing more than one-third of the c. 385,000 publicly available Populus ESTs. Clustering and assembly of 107,519 3'-end ESTs resulted in 14,451 contigs and 20,560 singletons, altogether representing 35,011 putative unique transcripts, or potentially more than three-quarters of the predicted c. 45,000 genes in the poplar genome. Using this EST resource, we developed a cDNA microarray containing 15,496 unique genes, which was utilized to monitor gene expression in poplar leaves in response to herbivory by forest tent caterpillars (Malacosoma disstria). After 24 h of feeding, 1191 genes were classified as up-regulated, compared to only 537 down-regulated. Functional classification of this induced gene set revealed genes with roles in plant defence (e.g. endochitinases, Kunitz protease inhibitors), octadecanoid and ethylene signalling (e.g. lipoxygenase, allene oxide synthase, 1-aminocyclopropane-1-carboxylate oxidase), transport (e.g. ABC proteins, calreticulin), secondary metabolism [e.g. polyphenol oxidase, isoflavone reductase, (-)-germacrene D synthase] and transcriptional regulation [e.g. leucine-rich repeat transmembrane kinase, several transcription factor classes (zinc finger C3H type, AP2/EREBP, WRKY, bHLH)]. This study provides the first genome-scale approach to characterize insect-induced defences in a woody perennial providing a solid platform for functional investigation of plant-insect interactions in poplar.
Mol Ecol 2006 Apr
PMID:Genomics of hybrid poplar (Populus trichocarpax deltoides) interacting with forest tent caterpillars (Malacosoma disstria): normalized and full-length cDNA libraries, expressed sequence tags, and a cDNA microarray for the study of insect-induced defences in poplar. 1662 54


1 2 Next >>