ISHS Acta Horticulturae 431: Tospoviruses and Thrips of Floral and Vegetable Crops
RESISTANCE TO TOMATO SPOTTED WILT VIRUS IN TOBACCO PLANTS TRANSFORMED WITH THE HIGH EXPRESSION VECTOR |
| Authors: | S. Tsuda, K. Yoshioka, Y. Ohdaira, I. Fujisawa |
| DOI: | 10.17660/ActaHortic.1996.431.42 |
| Abstract:
Transgenic Nicotiana tabacum cv. Samsun NN plants expressing translatable or untranslatable nucleocapsid (N) protein coding sequences (777 bases) of tomato spotted will virus (TSWV) were obtained. These plants were transformed via Agrobacterium tumefaciens with four types of pBIN19 constructs containing either CaMV35S or E12Ω promoter (a derivative of CaMV35S) and the translatable or untranslatable N gene. Most transgenic plants with E12Ω + translatable N gene accumulated N protein to a level comparable with TSWV-infected (healthy) tobacco plants. R0 plants showed no (or few) local lesions and no systemic symptoms after their leaves were inoculated with the homologous TSWV isolate. On the contrary, a large number of local lesions appeared on inoculated leaves of transgenic plants expressing CaMV35S + translatable N gene, CaMV35S + untranslatable N gene, or E12Ω + untranslatable N gene. These transgenic plants produced RNA transcripts to a level equal to the plants expressing E12Ω + translatable N gene. Almost all R1 plants with an E12Ω + translatable N gene had no local lesions. However, levels of the N protein in these plants were not consistent. Some of them expressed a negligible level of the N protein. Our results suggest that TSWV resistance is not correlated with high expression of the N protein. | |
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