تراریخته

Genetically modified (GM) plants are one of the great achievements of modern biotechnology in agriculture, which their cultivation has been increased in recent years. According to the international biosafety law, the import of genetically modified plants without the permission of Biosafety Committee into the country is prohibited. Therefore, we need an accurate method for assessing whether they are transgenic or not. In this study, samples of tomatoes were collected from various sources such as shops and greenhouses in Isfahan province to evaluate if they are transgenic. The initial screening of all samples was performed using primer pairs P35S F/R for CaMV35S promoter and NOS-1/NOS-3 for NOS terminator, amplified 195 bp and 180 bp of 35S promoter and NOS terminator sequences, respectively. The sequence of fragments was verified by comparison with known sequences in GeneBank and indicated a 100% homology, showing the studied samples are genetically engineered. The tomato samples were also tested for the presence of antisense polygalactoronase (PG) gene using the primer pair PG F/R, which amplified 384bp in all samples. Sequence analysis of this fragment resembled 100% similarity with the sequence of PG antisense gene in Gene Bank database. Results of this study showed that there is a transgenic tomato in the Iranian market. But, the consumers are not aware of its changed nature.

The hairy roots induced by Agrobacterium rhizogenes due to the stability and mass production in hormone free culture provide an appropriate tissue for secondary metabolite production, and the content of metabolites produced could be affected by bacterial strain. In the current study, the effect of different strains of A. rhizogenes including A4, A13 and 15834 on the percentage of hairy root induction of Echinacea purpurea (L.) moench. in the leaf and hypocotyl explants were studied. In another experiment, total phenolics and polysaccharides content of hairy roots were measured compared to the control (untransformed) roots. The results showed that the percentage of hairy root induction was significantly affected by bacterial strains, so that in E. purpurea leaves incubated by strains A13, 15834 and A4, the hairy root induction was 60%, 40% and 0, and in hypocotyl explants was 85%, 45% and 70%, respectively. Maximum total phenolic compounds were observed in A4 strain. As well, in comparison to control, the polysaccharide content in hairy root induced by strains 15834 and A13 increased and by A4 strain decreased significantly. Differences observed in this study about hairy root induction and secondary metabolites production could be due to different ability of A. rhizogenes strains in T-DNA transferring to plant cells.