ЭлБиб

269 / 592

PLANT GENETIC TRANSFORMATION, CELL SELECTION AND SOMATIC HYBRIDIZATION
TMVRESISTANCEOFTRANSGENICTOBACCOPLANTSSYNTHESIZING
DOUBLE-STRANDEDRNA
T.V.Korostyleva,O.S.Petrova, E.N.Andreeva, T.I.Odintsova, S.P.Smirnov,
B.A.Pukhal'skii.
Vavilov Institute o f General Genetics, RussianAcademy o fScienses, Moscow 117809
Russia. E-Mail:
The role of double-stranded RNA as a possible resistance mechanism
against vira l infection was analyzed. The transgenic tobacco plants
N.tabacum cv. Samsun nn with the introduced construct, which controls
the synthesis o f double-stranded RNA, and control plants were used in this
study. The stable inheritance o f the inserted construct in second and third
plant generations was demonstrated. For this study the third generation
plantlets were selected in plant growth medium with a kanamicin (50 mkg/
m l). Plants were infected with wild (vulgare) and vaccine (AT-16) TMV strains.
A t early stages after infection, the trans-genic plants did not d iffe r
morphologically from control plants. At late infection stages (1-1.5 months)
stunted growth o f transgenic plants was less pronounced then in control
infected plants.
Leaf proteins were extracted with acetate buffer (pH6.8) seven days
after infection. By SDS one- and 2D-electrophoresis, 2 new proteins were
revealed in transgenic infected plants. The amount of viral coat protein (both
attenuated and wild strains) was decreased in transgenic plants.
Ds-RNA was isolated using 20% SDS and 5M potassium acetate
according to De Paulo (1995). Three types o f ds-RNA molecules were
detected. 8-kb and 12-kb ds-RNAs were found both in transgenic and control
plants infected with wild TMV strains, while 0.6-kb ds-RNA was observed
only in transgenic plants.
Accordingly, the role of ds-RNA against viral infection wasdemonstrated;
however, the involvment of new proteins and ds-RNA molecules in this process
remains to be elusidated.
269
Научная электронная библиотека ЦНСХБ