Submitted to: International Organization of Citrus Virologists Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 11/7/2004
Publication Date: 11/30/2004
Citation: Febres, V.J., Moore, G.A., Lee, R.F. 2004. Development of pathogen-derived transgenic citrus for resistance against citrus tristeza virus. International Organization of Citrus Virologists Abstracts, Page 39. Interpretive Summary:
Technical Abstract: Technical Abstract: Citrus tristeza virus (CTV) is one of the most economically important citrus viruses in the world, having killed millions of trees on sour orange rootstock and through reductions in tree vigor and fruit size, quality, and yield by stem pitting of scions. We have developed over 100 transgenic grapefruit clones using genes from CTV: coat protein gene (p25), non-translatable coat protein gene, RNA dependent RNA polymerase (RdRp) sense, minor coat protein gene (p27), p20, 3=end-sense, and 3= end-antisense. Transformed plants were screened for expression of GUS, PCR amplification of the intended insert, and by Southern blot analyses for confirmation of gene insertion into the plant genome and to determine the copy number. Evaluation of transgenic plants was made by graft-challenge and aphid-challenge using a severe, stem pitting isolate of CTV which is easily aphid transmitted. One line has shown good resistance against CTV and two more clones appear to recover from the CTV infection. Of the 41 transgenic lines evaluated for CTV resistance to date, 13 have shown some degree of resistance.