000 02347nam a2200241Ia 4500
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100 _aSunderasan E
245 0 _aHevea genetic transformation: A molecular approach to enhance resistance to Corynespora leaf disease
260 _bInternational Workshop on Rubber Tree Breeding, IRRDB, Brazil, 4-7 April 2011
520 _aThe pathogenic fungus Corynespora cassiicola a serious threat to rubber trees (Hevea brasiliensis); the infected leaves develop necrotic lesions and abscise, leaving the tree unproductive. The destructiveness of C. cassiicola has been laegely attributed to cassiicolin, a secreted protein toxin of the fungus. Recombinant antibody technology coupled to genetic transformation offer hope to curtail the disease in Hevea. Single chain variable fragment (scFv) specific to cassiicolin could bind and deactivate the toxin in genetically modified rubber trees that harbour the functional antibody gene. A scFv phage library was constructed from cassiicolin immunized Balb/C mice spleen IgG heavy and light variable chains. Biopanning of the phage library yielded a scFv clone with high specificity to cassiicolin. Nucleotide sequence and deduced amino acid sequence information of the scFv were obtained. The hemmagglutinin (HA) tagged scFv expressed in Escherichia coli is discerned as a band at circa 30 kDa on SDS-PAGE. The corresponding band was detected by anti-HA IgG on a western immunoblot of the gel. Homology-based modeling was employed to create three-dimensional structures of the scFv antibody and cassiicolin, and binding (docking) of the antibody to the toxin antigen was simulated. Furthermore, deactivation of cassiicolin by the scFv was demonstrated by detached leaf bio-assay on selected susceptible Hevea clones. Efforts are underway to genetically transform Hevea clones with the cassiicolin-specific scFv gene to enhance resistance to Corynespora leaf disease.
650 _aCassiicolin
650 _aCassiicolin-swpecific scFv
650 _aCorynespora cassiicola
650 _aDetached Hevea leaf bioassay
650 _aGenetic transformation
700 _aBadarudin Badrul Ezam
700 _aKadir Rusni K
700 _aMalik Adeel
700 _aNathan Sheila
700 _aPujade-Renaud Valerie
700 _aYeang H Y
942 _cJS
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