Genetic Engineering of Peanut for Disease Resistance. P. OZIAS ...


11 Δεκ 2012 (πριν από 4 χρόνια και 7 μήνες)

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Genetic Engineering of Peanut for Disease Resistance

P. OZIAS-AKINS*, Y. CHU, C. NIU, X.Y. DENG, H. YANG, and S. HAZRA, Department of Horticulture, The
University of Georgia Tifton Campus, Tifton, GA 31793-0748.

The susceptibility of peanut to numerous pathogens makes it a prime target for genetic improvement by
insertion of genes from outside of the gene pool of Arachis. We have transformed peanut with putative
disease resistance genes using the technique of microprojectile bombardment. For Tomato spotted wilt
virus (TSWV), the nucleocapsid protein gene of the virus, controlled by viral or plant promoters, has been
introduced into peanut in either a translatable or non-translatable form. The non-translatable version
consisted of 403 bp from the nucleocapsid protein gene that was bombarded into peanut somatic embryos
as 1) the sense construct alone, 2) the antisense construct alone, or 3) the sense and antisense constructs
co-bombarded. Both sense and antisense sequences were driven by the actin 2 promoter from Arabidopsis.
Sense and antisense orientations could be distinguished by PCR of DNA from progeny plants. Insertion of
the gene(s) was verified by southern blot analysis and ranged from one up to 12 copies. Reverse-
transcriptase PCR results indicated that the N-gene was transcribed in most lines that contained either
sense or antisense genes. When the N-gene was present in both sense and antisense orientations,
transcription was rarely observed. The resistance to TSWV in these transgenic lines is being tested by
mechanical inoculation. In addition, a nonheme chloroperoxidase gene (CPO-P) from Pseudomonas
pyrrocinia, which has been reported to inhibit the growth of mycotoxin producing fungi, was introduced into
peanut. Antifungal properties are expressed in leaf tissue from plants growing in the greenhouse.