فهرست مطالب mohammad mahdi sohani

Salinity stress affects morpho-physiological and biochemical traits of plants. The transgenic Bt plants play a significant role in pest control, but their response and ability to cope with environmental stresses still need to be evaluated. Therefore, effect of salinity stress at 0, 50, 100, 150, and 200 mM on morphological, physiological, and molecular traits of T3 transgenic tomato plants containing cry1Ab gene (CH-Falat-Bt) was investigated and compared with that of the non-transgenic control (CH-Falat). Evaluation of the morphological traits (leaf area, root length, fresh and dry weight of roots) at different salinity levels revealed that CH-Falat-Bt transgenic plants are more tolerant to salinity stress compared to CH-Falat non-transgenic plants. The chlorophyll content at 150 and 200 mM salinity levels was 12 and 9% plants, respectively. Moreover, the amount of RWC, carotenoids, proline and soluble sugars increased significantly in transgenic plants as salinity levels increased. The relative expression of SOS1 and SOS2 genes showed a significant increase in all salinity levels in CH-Falat-Bt transgenic plants compared to CH-Falat non-transgenic plants. The amount of electrolyte leakage in the transgenic plants was significantly reduced compared to the non-transgenic plants. The results of morphological, physiological, and molecular investigations of CH-Falat-Bt transgenic plants confirmed that the undesirable effects of salinity stress on transgenic plants is much less than non-transgenic ones. in general CH-Falat-Bt transgenic plants are more tolerant to different applied salinity levels than the wild variety.

High temperatures causes serious damage to plants, including disruption of cell hemostasis, slowness or stagnation of growth and development, and even death. When plants are exposed to high temperatures, heat shock proteins (HSP) are induced in the cell. Among HSPs are Small heat shock proteins (sHSP), which act as chaperones. They bind to proteins that have been exposed to heat stress and prevent them from incorrectly folding. The Artemin protein isolated from Artemia urmiana has a a-crystallin domain, which is characteristic of sHSP. In order to characterize the functional genomic roles of the protein in plants, artemin gene was transferred to Arabidopsis. A statistical analysis using the factorial design method was performed including two independent transgenic genotypes (art-1 and art-2) along with a wild genotype Col-0 under heat stress at 45°C. Results showed that the interaction between heat stress factors and genotypes was significant at the 1% level for most traits including germination, seedling wet and dry weight, seedling length, total protein content, catalase enzyme activity, and malondialdehyde content. All the components of germination were adversely affected by the application of heat stress. However, the transgenics still had a significantly higher seed germination and plant growth than the wild-type plants. As a result of heat stress, transgenic plants had significantly higher catalase enzyme activity and total protein content, and lower malondialdehyde levels compared with wild type plants. The results indicated that Artemin transgen in plants may cause significantly higher plant resistance to heat stress and increase plant yield.

Pure DNA is essential in various techniques of molecular biology and its extraction from plants to produce large amounts of secondary metabolites is a difficult task. Alchemilla is known to synthesize a large number of secondary metabolites which reduce the quality of the extracted DNA. This study, aimed to set up a method for high-quality DNA isolation from Alchemilla leaf. We examined three extraction methods. Furthermore, a comparison concerning price, simplicity, and security is carried out. We optimized a CTAB-based method using increasing the volume and concentration of CTAB buffer, lysis time, and cold incubation period, performing six times dilutions, and three times precipitations, adding polyethylene glycol, and removing toxic or expensive materials. The results showed that, 260/280 and 260/230 ratios of extracted DNA by the optimized method with the concentration of 595–387 ng/µL were 1.75–1.82 and 1.56–1.68, respectively. The quality of extracted DNA by this method was significantly higher (p < 0.001) than that of other ways, so that all samples were positive for DNA, as assessed by electrophoresis and PCR. The optimized method was simple, effective, reproducible, relatively non-toxic, and inexpensive. The results revealed that, this method was successful in producing large amounts of high-quality amplifiable DNA.

In this experiment, a total of 360 one day-old female Ross 308 broiler chicks in a completely randomized design with a 2 × 3 factorial arrangement were allocated to 6 dietary treatments, each replicated five times with 12 birds per replicate. The included factors were two levels of green tea extract (GTE, 0 and 500 mg/kg diet) and three type of diets: 1- diet without dietary fat, 2- diet supplemented with soybean oil (SO) and 3- diet supplemented with Tallow (Ta). Use of GTE did not affect intestine microbial populations, intramuscular fat, oxidative stability of mat and performance in broiler chicken (p>0.05). Body weight gain and feed conversion ratio of chicks fed diet supplemented with SO or Ta was improved compared to the diets without fat (p<0.05). Use of SO compared to Ta and diets without fat led to higher and lower abdominal fat and carcass yield, respectively (p<0.05). GTE supplementation in diets high in fat was effective in decreasing abdominal fat percentage (p<0.05). The broilers that received green tea extract and soybean oil had a higher lactobacillus populations than those fed GTE with Ta (p<0.05). Dietary SO led to significantly greater intramuscular fat and thiobarbituric acid reactive substances (TBARS) values in thigh meat (p<0.05). Based on the findings of this study, despite the improvement in gut microbial populations and carcass fat content by GTE addition in diets high in un/saturated fats, its effect on intramuscular fat contents and muscle antioxidant capacity was not significant (p>0.05).

The most effective way to produce a plant resistant to glyphosate is manipulation of EPSPS enzyme in order to reduce its affinity to this herbicide. It is one of the vital enzymes in the shikimate pathway, which is responsible for producing aromatic amino acids and various secondary metabolites in plants and bacteria. Without an active enzyme, the organism will not be able to survive. In the present study, one of the important domains in the EPSPS enzyme was modified by site-directed mutagenesis using mega-primer method and one tube approach. Glycine in position 96 was modified to Alanine which was sub-cloned along with the wild-type gene into pPZPY122 plant binary vector. Hashemi cultivar of rice (Oryza sativa) was used for transformation using EHA105 strain of Agrobacterium tumefaciens by in planta method. T2 transgenic plants separately were evaluated to resistance to the gentamicin and glyphosate. Also, positive gene expression was confirmed by Quantitative PCR. Therefore, based on the results, these plants showed significantly a high degree of resistance to the herbicide.

Tomato leafminer (Tuta absoluta) is one of the important pests of tomato in Iran. It causes serve losses to tomato yield between 50 to 100% in the world. The cryIAb gene has been introduced into many plant species, including maize resulting in protection of the maize plants against corn borer larvae. In most studies, constitutive promoters such as CaMV35S were employed for genetic transformation; however the constitutive expression of genes led to changes in plant metabolic pathways due to permanent energy consumption in plants. Since, wound inducible promoter MPI (Maize Protease Inhibitor) posses more efficiency and strength than CaMV35S promoter. Therefore, in the current study, transgenic tomato (cv. Falat) plants harboring cryIAb gene under control of the MPI promoter were developed for the first time. The MPI promoter was isolated from maize and cloned into pPZP122 expression vector replacing the CaMV35S promoter. The cryIAb gene was isolated from pCIB4427 and cloned in pPZP122:MPI:cryIAb and the resulting construct was transformed into Agrobacterium AGL1 strain using In planta approach. Initial selection of the transgenic plants was carried out in media culture containing gentamicin. PCR analysis confirmed the presence of transgene in gentamycin-resistance plants in the first and second generations by rate of 62.5% and 75.58%, respectively. Protein dot blotting using anti-CryIAb polyclonal antibody confirmed the presence of protein in the second generation of transgenic lines. Based on the result of Tuta bioassay, transgenic plants demonstrated an enhanced resistance against Tuta. Thus, the wound inducible promoter MPI can be used in genetic transformation of crop plants if insecticidal protein-encoding genes (such as different types of cry) are used and therefore, it is important to be used when plants asked to express only when are being attacked by insect pests.

Nowadays, by genetic engineering and bioinformatics, large scale production of pharmacological recombinant proteins in Escherichia coli (E. coli) bacteria, which has unique expression properties, becomes a routine and economic imperative. In this study, periplasmic production of human growth hormone was investigated using bioinformatics methods.
The aim of this study was bioinformatic evaluation of 48 human signal peptides by reliable servers for expression analysis of human growth hormone in Escherichia coli. Accuracy and precision of 48 signal peptides were evaluated via powerful SignalP server. Physicochemical properties of remaining signal peptides were investigated using Genescript and Protparam servers. Solubility of protein, secretory activity of signal peptides after expression, and transmission mechanism of signal peptides were investigated using Solpro, ProtCompB and PRED-TAT, respectively.
Findings: Theoretically, proline rich protein HaeIII subfamily 1 (PRH1), C10orf99, and prolactin-releasing hormone (PRLH) signal peptides were predicted as the most proper signal peptides in fusion of human growth hormone protein, respectively.
Secretory expression instead of cytoplasmic expression provides benefits. This study results indicated that by examining different signal peptide sequences in fusion with human growth hormone protein, achieving signal peptides with potential and capability for high expression is possible. The accuracy of these results can be verified in future studies and experiments.

Fusarium prolifratum is a causal agent of Bakanae disease (root rot and crown rot) in rice (Oryza sativa L.) which result in sever reduction of plant growth and yield. Morever، it produces mychotoxin that cause toxication in human and animals. Piriformospora indica is a endophytic fungus that can induced systemic resistance against different plant pathogens. In the current study، rice plants were pre-inoculated with P. indica followed by infected with Fusarium prolifratum in order to study the endophytic effects on plant resistance against Bakane disease as well as possibility of non-chemical control of the disease. A mild typical symptoms of the Bakane disease were developed in rice plants pre-inoculated with P. indica and chalenged with the Fusarum. Activity of some antioxidant enzymes such as Proxidase (POD)، Ascorbat proxidase (POD) and catalase (CAT) were measured 4 days after inoculation with F. prolifratum in root and leaves. The concentration of the three enzymes were significantly higher in colonized plants with P. indica and challenged with F. prolifratum compare to non-colonized and control plants in root and leaves. These results suggest that P. indica might protect rice from necrotrophic pathogens through activating the plant antioxidant enzyme. Therefore، results of this research showed that the endophytic fungus P. indica can be used as one of the non-chemical methods for controlling Bakanae disease in rice.

in this study transgenic plants of sour orange (C. aurantium) that is an important citrus rootstock were produced by Agrobacterium-mediated transformation. Epicotyl and hypocotyl segments-derived explants were co-cultured with Agrobacterium strain EHA105 carrying pFGC5941 plasmid containsing CTV coat protein (p25) gene. One of the main objects of present research was to improve the direct in vitro organogenesis efficiency in C. aurantium. Therefore different combination of BAP (0, 1, 2 mg/L) and NAA (0, 0.25, 0.5 mg/L) were used in selective medium to culture transformed explants. The highest regeneration (57%) was obtained from explant treated with 2 mg/L BAP and 0.25 mg/L NAA. Effects of wounding and vacuum infiltration on transformation efficiency were evaluated either. The best transformation efficiency (11.25%) was obtained from explants that were vacuum infiltrated during transformation and subsequently were cultured in medium containing 2 mg/L BAP and 0.25 mg/L NAA. PCR analysis using two different genes were performed to confirm transformation. Micro grafting of transformed shoots were carried out on non-transgenic, in-vitro grown seedlings.