Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A wheat-Thinopyrum intermedium translocation line YW642 possesses the resistance to GAV serotype of barley yellow dwarf virus (BYDV), in which the resistance gene Bdv2 is derived from the chromosome 7X of Thinopyrum intermedium group 7. It is interesting to analyze BYDV accumulation content in the resistant and susceptible wheat plants for controlling BYDV disease and understanding the resistance mechanism against BYDV. In the paper, semi-quantitative reverse-transcription PCR (RT-PCR) was used to detect and quantify BYDV-GAV in the resistant and susceptible plants using specific primers for the coat protein (CP) and RNA-dependent RNA polymerase (RdRp) genes of BYDV-GAV serotype. On the inoculation site, the amount of the virus in the resistant wheat line (YW642) was much lower compared to the susceptible sib line (YW641). There was small amount of the virus could be detected in YW642 at 2-5 days post infestation (dpi), afterwards the amount of virus decreased and no virus could be detected at 14 and 16 dpi. In the uninoculated upper leaves, no BYDV was detected in YW642 from 1 to 14 dpi, while the virus could be detected at 3 dpi and then accumulated rapidly in YW641. These results showed at molecular level that the replication and/or movement of BYDV-GAV were strongly suppressed in YW642, presumably owing to the action of the BdV2 gene.
 ...
PMID:Molecular evidence of barley yellow dwarf virus replication/movement suppressed by the resistance gene Bdv2. 1620 Dec 38

Root-knot plant-parasitic nematodes (Meloidogyne spp.) account for much of the damage inflicted to plants by nematodes. The feeding sites of these nematodes consist of "giant" cells, which have characteristics of transfer cells found in other parts of plants. Increased transport activity across the plasma membrane is a hallmark of transfer cells, and giant cells provide nutrition for nematodes; therefore, we initiated a study to identify the transport processes that contribute to the development and function of nematode-induced feeding sites. The study was conducted over a 4-week period, during which time the large changes in the development of giant cells were documented. The Arabidopsis ATH1 GeneChip was used to identify the many transporter genes that were regulated by nematode infestation. Expression of 50 transporter genes from 18 different gene families was significantly changed upon nematode infestation. Sixteen transporter genes were studied in more detail using real-time reverse-transcriptase polymerase chain reaction to determine transcript abundance in nematode-induced galls that contain giant cells and uninfested regions of the root. Certain genes were expressed primarily in galls whereas others were expressed primarily in the uninfested regions of the root, and a third group was expressed evenly throughout the root. Multiple transport processes are regulated and these may play important roles in nematode feeding-site establishment and maintenance.
 ...
PMID:Nematode-induced changes of transporter gene expression in Arabidopsis roots. 1647 44

Amino acids represent the major form of reduced nitrogen that is transported in plants. Amino acid transporters in plants often show tissue-specific expression patterns and are used by plants to transport these metabolites from source to sink during development and under changing environmental conditions. We identified one amino acid transporter, AtCAT6, which is expressed in sink tissues such as lateral root primordia, flowers and seeds. Additionally AtCAT6 was induced during infestation of roots by the plant-parasitic root-knot nematode, Meloidogyne incognita. Quantitative reverse-transcriptase PCR revealed nematode inducibility throughout the duration of nematode infestation and in nematode-induced feeding sites. Promoter analyses confirmed expression in endogenous sink tissues and nematode-induced feeding sites. In Xenopus oocytes, AtCAT6 mediated electrogenic transport of proteinogenic as well as non-proteinogenic amino acids with moderate affinity. AtCAT6 transported large, neutral and cationic amino acids in preference to other amino acids. Knockout mutants of this transporter failed to grow on medium containing l-glutamine as the sole nitrogen source. Our data suggest that AtCAT6 plays a role in supplying amino acids to sink tissues of plants and nematode-induced feeding structures.
 ...
PMID:AtCAT6, a sink-tissue-localized transporter for essential amino acids in Arabidopsis. 1705 24

A novel virus, Brevicoryne brassicae virus (BrBV), has been identified in the cabbage aphid using a method based on the random amplification of encapsidated RNA. The complete sequence of the RNA genome of BrBV has been determined. The positive-strand genomic RNA is 10 161 nt, excluding the 3' poly(A) tail, and contains a single open reading frame (positions 793-9744) encoding a putative polyprotein of 2983 aa. The N-terminal part of the polyprotein shows similarity with the structural proteins of iflaviruses. The C-terminal part possesses consensus sequences of the helicase, cysteine protease and RNA-dependent RNA polymerase similar to those of iflaviruses and other picorna-like viruses. The highest sequence similarity observed was with iflaviruses from honeybee and an endoparasitic wasp. Replication and transmission of BrBV was not dependent on endoparasitic wasp infestation of the aphids.
 ...
PMID:A novel virus isolated from the aphid Brevicoryne brassicae with similarity to Hymenoptera picorna-like viruses. 1769 71

Iflavirus RNA was detected in honeybee colonies displaying unduly aggressive behavior and with no evidence of morphological alterations. Sequence analysis of the RNA-dependent RNA polymerase (RdRp) revealed that the iflavirus strain was more similar (> 99% aa) to Deformed Wing Virus (DWV), that has been associated with morphological alterations in bees, rather than to the newly-described Kakugo Virus (KV) (about 95% aa), that has been associated with increased aggressiveness. Therefore, the iflavirus strain detected in the Italian hives genetically resembled DWV but was apparently associated with a KV-like phenotype. RT-PCR detected the iflavirus RNA in the abdomen of the workers, and only in one case was the virus detected in the head. No viral RNA was detected in the drones, a pattern of virus distribution across the honeybee casts that is in apparent conflict with the higher rates of infestation of drones by the mite Varroa distructor. The identification of a virus with apparently intermediate features between DWV and KV open new perspectives on the patho-biological role of iflaviruses in honeybees.
 ...
PMID:Detection of a honeybee iflavirus with intermediate characteristics between kakugo virus and deformed wing virus. 1912 97

RNA-dependent RNA polymerases (RDRs) from fungi, plants and some invertebrate animals play fundamental roles in antiviral defense. Here, we investigated the role of RDR6 in the defense of economically important rice plants against a negative-strand RNA virus (Rice stripe virus, RSV) that causes enormous crop damage. In three independent transgenic lines (OsRDR6AS line A, B and C) in which OsRDR6 transcription levels were reduced by 70-80% through antisense silencing, the infection and disease symptoms of RSV were shown to be significantly enhanced. The hypersusceptibilities of the OsRDR6AS plants were attributed not to enhanced insect infestation but to enhanced virus infection. The rise in symptoms was associated with the increased accumulation of RSV genomic RNA in the OsRDR6AS plants. The deep sequencing data showed reduced RSV-derived siRNA accumulation in the OsRDR6AS plants compared with the wild type plants. This is the first report of the antiviral role of a RDR in a monocot crop plant in the defense against a negative-strand RNA virus and significantly expands upon the current knowledge of the antiviral roles of RDRs in the defense against different types of viral genomes in numerous groups of plants.
 ...
PMID:RNA-dependent RNA polymerase 6 of rice (Oryza sativa) plays role in host defense against negative-strand RNA virus, Rice stripe virus. 2214 75

In March 2011, interveinal yellowing and necrosis symptoms on middle and lower leaves were observed in tomato (Solanum lycopersicum L., cv. Castle Rock) plants grown in three adjacent greenhouses of the Agricultural Research Corporation at Wad Medani (Gezira State, Sudan). These symptoms resembled those caused by Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) (4) (genus Crinivirus, family Closteroviridae). Whitefly (Bemisia tabaci) infestation was also observed in these greenhouses. Total RNA was extracted by TRIzol Reagent (Invitrogen, Carlsbad, CA) from symptomatic leaves and analyzed by dot-blot hybridization with digoxigenin-labelled RNA probes to the coat protein (CP) gene of ToCV and to the minor coat protein (CPm) gene of TICV. Positive signal was obtained only with the ToCV probe. Reverse transcription (RT)-PCR reactions were performed with two pairs of primers specific for the detection of ToCV, MA380(+) (5'-GTGAGACCCCGATGACAGAT-3') and MA381(-) (5'-TACAGTTCCTTGCCCTCGTT-3'), specific to the CP gene (ToCV RNA 2) (3), and MA396(+) (5'-TGGTCGAACAGTTTGAGAGC-3') and MA397(-) (5'-TGAACTCGAATTGGGACAGA-3'), specific to the RNA-dependent RNA polymerase (RdRp) gene (ToCV RNA 1) (1). DNA fragments of the expected sizes (436 and 763 bp, respectively) were obtained, thus supporting the presence of ToCV in the symptomatic samples. Amplified DNA fragments were cloned in pGEM-T Easy vector (Promega, Madison, WI) and one clone per amplicon was sequenced (Macrogen Inc., Seoul, South Korea). The highest nucleotide sequence identity of the CP gene fragment obtained (GenBank Accession No. JN411685) was 99.2% related with North American ToCV isolates from Florida (DQ234674), Colorado (DQ234675), and Georgia (HQ879842), while the RdRp gene fragment (JN411686) was more closely related (99.0%) to the Spanish AT80/99 isolate (DQ983480). Although yellowing symptoms similar to those reported here have been observed sporadically during the last few years in open-field tomato crops in the state of Gezira, additional studies are needed to determine the prevalence and economic impact of ToCV infections in tomato cultivation in Sudan. To our knowledge, ToCV has been found in continental Africa only in Morocco and South Africa, in the Mediterranean climate areas in the northern and southern edges of the continent, respectively (2). The finding of ToCV infecting tomato in Sudan raises the question of whether this virus is emerging also in other tropical areas of the continent and illustrates the need to monitor whitefly-infested areas within Africa for the presence of ToCV. References: (1) G. Lozano et al. J. Virol. 83:12973, 2009. (2) J. Navas-Castillo et al. Annu. Rev. Phytopathol. 49:219, 2011. (3) H. P. Trenado et al. Eur. J. Plant Pathol. 118:193, 2007. (4) G. C. Wisler et al. Plant Dis. 82:270, 1998.
 ...
PMID:First Report of Tomato chlorosis virus Infecting Tomato in Sudan. 3073 91