Tkansgenic Burley and Flue-Cured Tobacco with Resistance to Four Necrotic Isolates of Potato Virus Y

Abstract

Transgenic burley (cultivars KY 14, NC3433-33, and TN90) and fluecured (cultivar K326) tobacco with resistance to four necrotic isolates of potato virus Y {WY) were constructed. These tobacco cultivars were transformed with a chimeric gene designed to express the coat protein (CP) from the necrotic Chilean isolate of PVY. CP expression among plants was undetectable by indir~etn zymelinked immunosorbent assay and Western blot (imrnunoblot) analys~s. Transgenic R, plants that harbored from one to five neomycin phosphotransferase I1 (NFT 11) transgene loci were identified. Although the NPT 11 and the PVY CP chimeric genes were linked within a common T-DNA, no correlation was found betwwn the number of NPT I1 and CP transgenes. Inoculation of 41 independent tr;msgcnic KYI4 plants with PVY-Chilean identified eight resistant plants, while inoculation of 30 transgenic K326 plants identified six resistant plants. Inocutation of 17 transgenic NC3433-33 R, plants with PVY-Chilean ident~fied six resistant plants, while inoculation of SO transgenic TN90 % plants with PVY isolate VAM B resulted in nine resistant plants. Progeny derived from PVY-inocu!ated but symptomless R, plants were also reststant to the Chilean. Europe 61, MSNC ,-Canada, nnd VAM I3 isolates of WY, demonstrating sexual transmission of the transgenes that condition resistance. We discuss the ability of the PVY-Chilean CP gene to protect transgenic tobacco K326, KY 14, NC3433-33, and TN90 from infwtion by four necrotic isolates of PVY. The flue-cud tobacco cultivar K326, which carris a gene simultaneously conferring resistance against root-knot nematode and susceptibility to PVY strain MSNR, is protected against this strain when transformed with the PW-Chilean CP genc. ArddiliomI hywuTdF: capsid protein gene-mediated resistance, potyviruses, virus resistance.