StatusThe thesis was presented on the 20 December, 2007
Approved by NCAA on the 28 February, 2008
Abstract– 0.86 Mb / in romanian
ThesisCZU 577.218: 575.822: 632.954: 633.71
4.09 Mb /
For the first time there were analyzed transgenic tobacco plants that contain CsLFY and bar genes, being under 35S CaMV promoter control in T1 generation, in normal conditions and after treatment with Basta herbicide. The presence, inheritance and expression of this transgenes at molecular and morphological and physiological levels were analyzed.
The transgenes integration in genome was shoved by PCR analysis, and expression of these genes - at the level of transcription and translation processes. There were detected proteins with Mr 44 kDa and 23 kDa, which corresponded to expression products of CsLFY and bar genes, showing constitutive expression in different plant organs.
The majority of tobacco lines (10 on 13) had demonstrated Mendelian inheritance of bar gene in T1 generation, where the ratio of segregation was 3:1 (hemizygous in T0). One line had been certified by 15:1 segregation ratio (dihemizygous in T0). But, at two lines the segregation ratio was non-Mendelian (1:1, 1:3).
After these investigations, it was revealed that in normal conditions transgenic tobacco plants were characterized by earlier flowering, greater plant dimensions, and increase of proteins content, hydrogen peroxide and catalase activity in leaves.
Another object of this research was the analysis of influence of bar gene in induction of genetic and physiological mechanism of Basta herbicide resistance. The results showed that the level of protein content decreased in dependence to line and was associated to herbicide resistance. Electrophoresis analysis revealed decrease of majority electrophoresis strips, in special those with middle and small molecular weight, inclusively Rubisco subunits. Basta herbicide in leaves induced increase of polypeptides with Mr 39 kDa, supposed to be GS1 enzyme, and protein with Mr 164 kDa, determined as Fd-GOGAT enzyme, both involved in nitrogen metabolism and are implicated in increase of herbicide resistance.
Transgenic tobacco plants were analyzed in vitro and in vivo for tolerance to Basta herbicide. Thus, treatment with this herbicide induces decrease of water, proteins and pigments content, photosynthesis intensity, tissues chlorosis and necrosis, retardation of plant growing.
For the first time there was done the test of GMPs by different methods, including PCR. Preventive results did not show the presence of genetic modifications in potato and tomato, cultivated in Moldova.