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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-7-10
pubmed:abstractText
Citrus tristeza virus (CTV) is a major pathogen of Citrus. A single dominant gene Ctv present in the trifoliate relative of Citrus, Poncirus trifoliata confers broad spectrum resistance against CTV. Refinement of genetic maps has delimited this gene to a 121 kb region, comprising of ten candidate Ctv resistance genes. The ten candidate genes were individually cloned in Agrobacterium based binary vector and transformed into three CTV susceptible grapefruit varieties. Two of the candidate R-genes, R-2 and R-3 are exclusively expressed in transgenic plants and in Poncirus trifoliata, while five other genes are also expressed in non-transformed Citrus controls. Northern blotting with a CTV derived probe for assessment of infection in virus inoculated plants over a span of three growth periods, each comprising of six to eight weeks, indicates either an absence of initiation of infection or it's slow spread in R-2 plant lines or an initial appearance of infection and it's subsequent obliteration in some R-1 and R-4 plant lines. Limited genome walk up- and downstream form R-1 gene, based on it's 100% sequence identity between Poncirus and Citrus, indicates promoter identity of 92% between the two varieties. Further upstream and downstream sequencing indicates the presence of an O-methyl transferase and a Copia like gene respectively in Citrus instead of the amino acid transporter like gene upstream and a sugar transporter like gene downstream in Poncirus. The possibility of recombinations in the resistance locus of Citrus and the need for consistent monitoring for virus infection and gene expression in the transgenic Citrus trees is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0167-4412
pubmed:author
pubmed:issnType
Print
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
399-414
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:16830176-Blotting, Northern, pubmed-meshheading:16830176-Blotting, Southern, pubmed-meshheading:16830176-Chromosome Walking, pubmed-meshheading:16830176-Citrus paradisi, pubmed-meshheading:16830176-Cloning, Molecular, pubmed-meshheading:16830176-Closterovirus, pubmed-meshheading:16830176-Genes, Plant, pubmed-meshheading:16830176-Genetic Vectors, pubmed-meshheading:16830176-Glucuronidase, pubmed-meshheading:16830176-Plant Proteins, pubmed-meshheading:16830176-Plant Shoots, pubmed-meshheading:16830176-Plants, Genetically Modified, pubmed-meshheading:16830176-Poncirus, pubmed-meshheading:16830176-Promoter Regions, Genetic, pubmed-meshheading:16830176-Recombination, Genetic, pubmed-meshheading:16830176-Rhizobium, pubmed-meshheading:16830176-Sequence Analysis, DNA, pubmed-meshheading:16830176-Transformation, Genetic, pubmed-meshheading:16830176-Transgenes
pubmed:year
2006
pubmed:articleTitle
Refinement of the Citrus tristeza virus resistance gene (Ctv) positional map in Poncirus trifoliata and generation of transgenic grapefruit (Citrus paradisi) plant lines with candidate resistance genes in this region.
pubmed:affiliation
Division of Gastroenterology, Department of Internal Medicine, University of Texas Medical Branch, 1108 The Strand, 301 University Blvd, Room 215-216, Galveston, TX 77555-0632, USA. marai@utmb.edu
pubmed:publicationType
Journal Article