مجله زیست فناوری گیاهان زراعی
پیاپی 11 (پای ی ز 1394)

Diarrheal diseases have been considered as one of the most major world health problems in all age categories. Among all the pathogens caused to diarrhea, entrohemorrhagic Escherichia coli (EHEC) and Vibrio cholerae are the most important agents. E. coli O157:H7 as the most important serotype of EHEC bacteria caused diarrhea by producing STX2 toxin. In vibrio cholerae the cholera toxin (CTX) also is the main virulence factor that leads to diarrhea. Both of these toxins are belong to AB5 family and due to non-toxicity and natural immunogenic characteristic of B subunit, it could be introduced as an appropriate candidate for immunogenicity against these toxins. Plant seeds are an effective biological bioreactor for production of recombinant immunogenic antigens and also foreign proteins can be expressed in plants with the native structure. In this research, the production of recombinant protein composed of binding subunits of STX2 and cholera toxin was evaluated in canola seed as an oral vaccine candidate. The SC construct composed of (stx2B and ctxB) was subcloned to plant vector under the control of canola seed specific promoter (fae) and transformed to Agrobacterium tumefaciens. Then the recombinant vector was transformed to plant host via Agrobacterium mediated transformation. Transgenic plants was evaluated and the amount of chimeric protein expressed in transgenic canola seed was determined by semi quantitative ELISA and subsequently the amount of chimeric proteins was estimated 40 milligram per 1 gram seed. The results showed that the canola seed can efficiently produce recombinant protein.

The spot blotch disease caused by Bipolaris sorokiniana is one of the most important diseases of wheat worldwide. The knowledge about genetic structure of fungal pathogens is important to design appropriate strategy to control the disease. In this study, a total of 46 samples were isolated, purified and characterized from samples collected from Mazandaran and Golestan provinces. Pathogenicity tests showed that isolates were able to cause typical spot blotch symptoms on Bulani as the susceptible cultivar. Genetic diversity analysis of isolates using 17 ISSR and RAPD markers showed that out of 179 amplified bands, 98 were polymorphic. The average of amplified bands for each marker was 10.4, while the average of polymorphic bands was calculated 5.6 for each marker. The average PIC value was 0.32 ranging from the highest PIC value (0.41) for the ISSR marker, UBC874, to the lowest PIC value (0.18) for the RAPD marker, OPF2. Cluster analysis of banding pattern data showed that populations of this fungus had a high genetic diversity. Based on bootstrap analysis the isolates were differentiated with a high genetic distance to seven distinct groups. Highly distinct clusters belonging to different geographic regions revealed that there were high genetic differences between fungal populations indicating that fungal populations might be adapted to different climate regions.

Detection of foreign genes in genetically modified (GM) plants is very important for proving the effectiveness of genetic engineering procedure and determination of GM plants. In the present study a very sensitive and convenient fluorescence nanobiosensor for rapid detection of GM crops based on Fe3O4/Au core/shell nanoparticles was developed. Specific site of 35S CaMV, a well studied gene promoter in plant genetic engineering was used as the DNA sequence target. The core/shell Fe3O4/Au magnetic nanoparticles were synthesized to utilize their magnetic properties and improve their DNA functionalization. Fe@Au nanoparticles were functionalized by bounding of single stranded DNA (ssDNA) probe through sulfhydryl group at 5ʹ phosphate end. Then complementary target ssDNA were hybridized with immobilized ssDNA probe. Methylene blue was selected as a fluorescence probe. It was shown that methylene blue had significant interaction with hybridized DNA. Upon the addition of the target ssDNA, fluorescence intensity decreased in linear range by concentration of ssDNA from 3×10-7 to 2.2×10-9 M with detection limit of 1.2×10-10 M. The nanobiosensor enabled us to detect the transgenic crops through convenient and reliable simple method.

Identification and quantification of proteins and genes that expressed in the salinity stress conditions could lead to better understanding of the response mechanisms. So, in this study iTRAQ comparative proteomic method was used to investigate the protein changes and quantification of them under salinity stress. Then, more studies about the function of identified genes were done using gene expression and co-expression data obtained from databases and analysis of related sequences. According to the results of iTRAQ-2DLC-MS/MS a set of proteins including P5CS1, KIN1, KIN2, ERD10, ERD14 and COR47 were identified. Results showed that expressions of the related genes were not just restricted to salinity stress. They were also involved in other osmotic stresses. Gene network based on identified proteins was evaluated by String software. Based on the results, during the expression of these genes, protective compounds such as compatible solutes, dehydrin proteins and etc. were produced in the cells. Presence of the compounds led to induction of resistance and tolerance mechanisms in plants against osmotic stress such as salinity.

Salinity stress is one of the abiotic stresses which threaten plant species. Achieving any progress in breeding for tolerance to stresses needs existence of genetic diversity. In this research, reaction of 53 sunflower mutant lines seedlings accompanied by their parental line was studied in several salinity levels including 0, 2, 4, 6, 8 ds/m. Also, in molecular experiment, genetic diversity of mutant lines was inspected using AFLP markers. Results revealed significant differences among the studied lines in each of salinity level based on seedling characteristics. Two hundreds loci were amplified using 17 combinations of AFLP primers in the studied lines. Analysis of population structure classified studied mutant lines in two subgroups. Considering association mapping, 43 AFLP markers had significant relation with seedling characteristics. Phenotypic variance of the identified markers varied between 0.13 and 0.42.

Borago officilalis, one of the oldest medicinal plants that is consumed in iran and other regions word. The considering importance of medicinal Borago officilalis, abundance of dry land, confroting ability with environmental stress by this plant, it seems necessary until done one study with the folowing goals. The chief goal of this research is to look for any effects of hydro stresses on proline biosynthesis, protein quantity, growth and change high consumption elements like K, S, P & N at hydroponic conditions. According to the results, there was a reduction in the weight of dry / wet root and aerial sections in any plants under hydro stress treatment in comparison with witness ones. The mentioned reductions were significant at aerial sections. There was a decrease in K quantity at root section with an increase at aerial parts. Also there was an increase in quantity of high consumption elements like N, P & S of root and a reduction of the same at aerial sections. Drought stress decreases the amount of protein in the plant shoots and roots compared to control. Proline contents in leaves and roots significantly increased under drought stress compared to control.