Evidence for sense RNA-mediated protection to PVYNin tobacco plants transformed with the viral coat protein cistron
✍ Scribed by René A. A. Vlugt; René K. Ruiter; Rob Goldbach
- Book ID
- 104622207
- Publisher
- Springer
- Year
- 1992
- Tongue
- English
- Weight
- 940 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0167-4412
No coin nor oath required. For personal study only.
✦ Synopsis
The coat protein (CP) cistron of the tobacco veinal necrosis strain of potato virus Y (PVYN), supplemented with translational start signals, was cloned into an Agrobacterium tumefaciens Ti transformation vector. Transformation of tobacco leaf discs resulted in 99 transgenic lines which were subsequently analysed for the presence and expression, at both the transcriptional and translational level, of the CP-gene. Although CP-specific RNA transcripts were produced in all plants no CP could be detected by several sensitive immunological techniques. Upon mechanical inoculation of progeny lines of selfpollinated original transformants (S 1) with PVY N, protection levels of 20 and 95 ~o, respectively, could be observed in two out of ten lines tested. This level of protection increased to 100~o in the $2 progeny obtained from self-pollination of virus-protected S 1 plants.
Transformation of tobacco leaf discs with a PVY N CP construct from which the ATG start codon had been removed by site-directed mutagenesis resulted in 57 transgenic lines that all produced CPspecific transcripts. Mechanical inoculation with PVY N of S 1 progeny plants of several of these lines resulted in resistance to a similar level and extent as in the S 1 progeny of plants transformed with the intact CP cistron. The results obtained strongly suggest that the resistance observed in the transgenic plants is principally based on the presence of PVY N CP RNA sequences rather than on the accumulation of viral coat protein.