Qualitative and Quantitative Variations in Protein, Chlorophyll and Carotenoid Contents in Brassica napus Transformed by Antisense Glutamine Synthefase

Analysis of transgenic plants is very important in gene transfer programs. In this research, the second generation (T1) of transgenic brassica napus which was transformed by antisense of Glutamine synthetase (GS) gene was studied from the view of total soluble protein content of leaf, total chlorophyll and protein patterns (SDS-PAGE) using seeds of Brassica napus .Protein concentration was determined by a calorimetric method described by Bradford method. Chlorophyll (a, b) and carotenoid contents were determined by spectrophotometry. The total soluble protein content of Brassica napus leaves increased from YG stage, reached a maximum level during MG2 and, after this, decreased with the progress of SS stage. Comparison of the total soluble protein between different treatments showed the highest level in the A2 plant and the least in the A6 plant. Comparisons with chlorophyll a and b were not significant between different treatments, but different stages showed significant differences with maximum and minimum levels obtained in the MG1 and SS, respectively. Protein patterns were also studied using SDS-PAGE method. No new band was recognized in the MG1 stage, but the density of some protein patterns was shown in YG and MG2 stages. In YG stage, differences were seen among the A5, A3, A4 and A6 with W.T on 41 KDa weighty position and also between the A1 and A2 with W.T treatment on 23/6 KDa. Considering the molecular weight GS1 subunit of glutamine synthetase (41 KDa) and the similar conditions in growth, protein extraction and macro molecular analysis in transgenic and control plants, we can tell that the difference shown in transgenic plants are probably due to the effect of the antisense of glutamine synthesis gene in this plant.