جستجوی مقالات مرتبط با کلیدواژه « Transgenic Plant » در نشریات گروه « گیاهپزشکی »

One of the most pathogenic viruses in Solanaceous plants is Potato X virus (PVX) which causes systemic mosaic spots and economic loss in Nicotiana tabacum. Use of the tobacco resistance varieties is the best method in management of this disease. In this study, to establish the tobacco plants resistant to PVX, an RNAi construct was designed for a 400 bp fragment of PVX’s P25 gene which is a suppressor of RNA Silencing in plant. The P25 fragment was amplified with specific primers by PCR and was cloned in two steps (in sense and antisense directions) into the pFGC5941 plasmid. Then, the RNAi construct was transformed from recombinant plasmid into the tobacco explants (Samsun) by means of Agrobacterium cells. The transgenic plants were identified by selection on Basta containing media and propagated, followed by molecular and phenotypic analyses. PCR test using plant’s DNA confirmed the presence of the transgene in transgenic plants. The next generation of the transgenic plants was inoculated with PVX in greenhouse. ELISA using anti-PVX-CP antibody showed that three transgenic lines are resistant to PVX. Molecular confirmation of three tobacco resistant lines was performed by RT-PCR using plant RNA and CP-specific primers and PVX did not detected in transgenic plants. This study resulted in production of three tobacco lines resistant to PVX. Study of their resistance in the field condition is in progress.

Study of the effects of genetically modified plants on non-target arthropods, is one of the most important research on transgenic plants safety. These plants are able to affect on natural enemies, directly and/or indirectly. So, in this study, the effect of feeding on Bt cotton and prey (Bemisia tabaci Gennadius) reared on Bt cotton was determined on predatory bug, Macrolophus pygmeus Rambur. Four diets including Bt-cotton Bemisia tabaci (first group), non Bt-cotton Bemisia tabaci (second group), Bt-cotton (third group), non Bt-cotton (forth group) were used in this experiment. The results showed that Bt-cotton significantly affected development time and fecundity of the predator. Developmental times of nymphs in the first, second, third and fourth groups were estimated to be 19.85±0.32, 16.08±0.24, 29.42±0.45 and 23.11±0.23 days, respectively. In addition, mean number of eggs laid in the non Bt-cotton Bemisia tabaci treatment were significantly more than other groups (32.778±0.97), although no significant differences were found on fecundity between Bt-cotton and non Bt-cotton treatments. According to the obtained results, the Bt-cotton potentially could have negative effect on the biological parameters of M. pygmeaus severely and applying transgenic plants as one of integrated pest management agent, needs still more experiments and attentions.