Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0008272 (chlorosis)
 2,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tagetitoxin, a chlorosis-inducing phytotoxin produced by Pseudomonas syringae pv. tagetis, inhibits RNA synthesis directed by chloroplast RNA polymerase. In isolated chloroplasts, tagetitoxin quickly and specifically reduced the incorporation of [3H]uridine into RNA. When it was added to transcriptionally active chloroplast protein extracts, the toxin directly inhibited incorporation of [32P]UTP into RNA. In addition, tagetitoxin inhibited in vitro RNA synthesis directed by the RNA polymerase from Escherichia coli. In vitro transcription reactions directed by chloroplast RNA polymerase or E. coli RNA polymerase are inhibited at tagetitoxin concentrations less than 1 microM. Nuclear RNA polymerase II purified from wheat germ was only affected at tagetitoxin concentrations greater than 100 microM during in vitro transcription. Tagetitoxin concentrations as high as 1 mM did not affect in vitro transcription reactions directed by RNA polymerase from bacteriophage T7 or SP6.
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PMID:Tagetitoxin inhibits RNA synthesis directed by RNA polymerases from chloroplasts and Escherichia coli. 168 34

ABSTRACT Tomato chlorosis virus (ToCV) is the second whitefly-transmitted, phloem-limited, bipartite closterovirus described infecting tomato. ToCV is distinct from tomato infectious chlorosis virus (TICV), based on lack of serological and nucleic acid cross-reactions and differences in vector specificity. TICV is transmitted only by the greenhouse whitefly (Trialeurodes vaporariorum), whereas ToCV is transmitted by the greenhouse whitefly, the banded-wing whitefly (T. abutilonea), and Bemisia tabaci biotypes A and B (B. argentifolii). Double-stranded (ds) RNA analyses of ToCV show two prominent dsRNAs of approximately 7,800 and 8,200 bp, with several small dsRNAs. Digoxigenin-11-UTP-labeled riboprobes derived from cDNA clones representing portions of RNAs 1 and 2 were used in Northern blot hybridizations to detect two large nonhomologous dsRNAs and a subset of smaller dsRNAs. These probes were used in dot blot hybridizations to detect ToCV in infected tomato. Inclusion bodies and cytoplasmic vesicles were consistently observed in phloem tissues of ToCV-infected Nicotiana clevelandii. Computer-assisted sequence analysis showed significant homology between ToCV clones that hybridize specifically with RNAs 1 and 2 and the lettuce infectious yellows virus methyltransferase of RNA 1 and the HSP70 heat shock protein homolog of RNA 2, respectively. Thus, ToCV is another member of the growing subgroup of bipartite closteroviruses transmitted by whiteflies.
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PMID:Tomato chlorosis virus: a new whitefly-transmitted, Phloem-limited, bipartite closterovirus of tomato. 1894 18