NICOTIANA TABACUM CV.SAMSUN سيب زميني در گياه Y انتقال و بيان ژن پروتيين پوششي سويه نكروتيك ويروس

Assessment of virus resistance in transgenic Nicotiana tabacum cv. Samsun lines against three Iranian isolates of potato virus Y

Tobacco plants (Nicotiana tabacum cv. Samsun) were transformed by coat protein gene of potato virus Y necrotic strain (PVY^N-CP) using pBIN19 binary vector and Agroinoculation method. The primers designed so that the inserted PVY-CP transgene had not any start codon and so, it was unable to be translated into coat protein product.. Resistance of 31 transgenic Nicatiana tabacum cv. Samsun lines containing PVY coat protein transgene (PVY^N-CP), were evaluated against the mechanical challenge inoculation of 3 prevalent Iranian PVY strains. On the basis of biological and serological properties, 3 Iranian PVY isolates include PVYn-H, PVYn-Mz (necrotic strain of PVY) and PVYo-Ar (an Ordinary strain). Symptom evaluation and ELISA tests showed that after challenge inoculation of 31 transgenic lines with PVYn-H, PVYn-Mz and PVYo-Ar isolates, 5, 4 and 0 lines showed resistant phenotype, 9, 10 and 2 lines showed moderate symptoms of the disease and 17, 17 and 29 lines showed susceptible phenotype, respectively. Using TAS-ELISA and Western-blot analysis, the protein product of PVY^N-CP transgene could not be detected in any of 31 transgenic lines. It seems that an RNA mediated resistance is responsible for resistance in the PVY-CP transgenic tobacco plants. In Nicotiana species, natural resistance sources to PVY infection are poor and development of engineered resistance sources against PVY infections would be useful.