TOWARDS IMPROVED INSECT RESISTANCE OF PAPAYA BY TRANSGENIC EXPRESSION OF SNOWDROP LECTIN

Authors: MCCAFFERTY, HEATHER - HI AG RES CNT; Moore, Paul; ZHU, Y. - HI AG RES CNT

Submitted to: World Congress on In Vitro Biology
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2004
Publication Date: 5/22/2004
Citation: McCafferty, H., Moore, P.H., Zhu, Y.J. 2004. Towards improved insect resistance of papaya by transgenic expression of snowdrop lectin. 2004 World Congress on In Vitro Biology, 40, p52-A, abstract P-2039.

Interpretive Summary:

Technical Abstract: Papaya (Carica papaya L.) is an important fruit crop of the tropics. Productivity is often limited by susceptibility to a number of natural enemies, including aphids, leafhoppers, mites and nematodes. Transgenic insect-resistant plants have been developed through the introduction and expression of genes encoding plant defense proteins such as protease inhibitors or lectins, which have anti-metabolic action against insects. Here we are targeting papaya pests by introducing a gene encoding a lectin with proven entomotoxic properties. The lectin gene, GNA, originally isolated from bulbs of snowdrop (Galanthus nivalis), was placed into the pBI121 binary vector containing the NPTII gene as a selectable marker. Expression of the lectin gene was controlled by a constitutive 35S promoter. Bombarded embryogenic calli of the cultivar Kapoho were selected on tissue growth media containing G418. Integration of the transgenes in surviving plants was confirmed by molecular analysis. We have obtained a number of independent lines. Western blotting showed that the recombinant protein had a similar molecular weight to the native snowdrop one. Biological activity of the recombinant protein was shown through an agglutination assay. Further analysis of the papaya lines will be presented.