جستجوی مقالات مرتبط با کلیدواژه « Transgenic » در نشریات گروه « زیست شناسی »

In most countries today the area under cultivation of transgenic crops has increased due to the increasing population.In Iran, there is no system for labeling transgenic products.Although baby food is one of the most important needs for growth and health of the baby, it is no exception.Therefore, in this study,we try to identify the transgenic products by PCR by examining the internal control gene Lectin and Camv 35S Promoter gene transcriptome.25 soybean samples were collected from shops and Twenty-five samples of baby food were collected from pharmacies in Tehran. Samples were extracted with TLAB brand tissue extraction kit. After analyzing the concentration and quality of DNA extracted by the nanodrop machine, the samples were screened by PCR.25 soybean samples were analyzed for 23 of the total samples (%92) for the presence of Lectin internal gene and 15 samples from all samples (%63) had Camv 35S Promoter gene.Of the 25 samples of baby food, 20 (%83) were positive for the presence of the inner gene,Lectin positive, and 13 (%52) were positive for Camv 35S Promoter gene transformation index. None of the products containing Camv 35S Promoter gene, indicating that the product was transgenic, were not labeled.It can be concluded that the rate of transgenicity in the samples tested is significantly higher.In baby foods, the transgenicity rate of Camv 35S Promoter gene was higher in Iranian samples than in foreign samples. In soybean samples, Camv 35S Promoter gene was present in Iranian products, while none of the samples tested had transgenic label

Rice (Oryza sativa L.) is the major food source for the most of people of the world. In the last few decades, the classical, mutational and molecular breeding approaches have caused enormous increase in rice productivity with the development of novel rice varieties. Stagnation in rice yield has been reported in recent decade because of emergence of pests and phyto pathogens, climate change, and other environmental issues. The CRISPR/Cas9 system has all genome editing capabilities, e.g., knock-in, knockout, knockdown, and expression activation. Researchers have been successful in editing genes controlling traits such as number of panicles per plant, number of seeds per panicle, grain weight, rice maturity, plant hormone synthesizing genes, amylose content, gelatinization temperature, grain length and width, as well as resistance to abiotic and biotic stresses. The shift of research toward the utilization of CRISPR/Cas9 systems for targeted mutagenesis could be a promising approach for overcoming the barriers to breeding of improved rice. In this review, the progress in rice by employing the CRISPR/Cas9 editing system and its famous applications have been discussed. It is seemed that the CRISPR/Cas9 and associated genome editing tools have taken in a revolutionary change in rice improvement which is very important for meeting the demands and ensuring the requirement of rice for future generations.

Due to population growth in the coming years, adequate food supply is the world's biggest problem, and it seems that one way to meet this need is to produce transgenic products. Transgenic products are created using modern technology to create or enhance a desirable property, such as increasing resistance to weeds or improving nutritional properties. The advantages of transgenic products include their resistance to pests, diseases and non-biological stresses. Given that Iran is one of the countries that is a member of the International Biosafety Protocol and the competent legal authorities are responsible for detecting transgenic items and assessing their safety, therefore, identifying and examining the safety of these products is of particular importance. In this paper, we have tried to examine the new methods of identifying and tracking transgenic processes.

Entomopathogenic nematodes belonging to Heterorhabditidae and Steinernematidae families are the most effective insecticidal pathogens. The bacterium Photorhabdus luminescens symbiont of Heterorahbitis bacteriophora (Heterorhabditidae) is located in the intestines of its symbiotic nematode, and produce several pathogenic agents, toxic and antimicrobial compounds that can kill the host insects as well as non-symbiotic nematodes, including plant pathogenic nematodes. Due to the pathogenicity and the ability to infect a wide range of insect pests, the relationship of Ph. Luminescens - H. bacteriophora is a promising option for mass production of biological control agents in agriculture, considering the wide range of hosts and non-impact on non-target organisms and the environment, provides effective control of different species of pest insects with a biocontrol agent rather than several chemical compositions. In addition, the successful transferring of the tcdA gene, which acts as an insecticidal protein against the herbivorous insects, from Ph. luminescens to Arabidopsis thaliana in order to control herbivorous pests, increases the possibility of replacing this bacterium with Bacillus thuringiensis in production of transgenic plants. In this paper, the introduction of Ph. luminescens and its features for use in pest management are discussed.

Canola (Brassica napus L.) is known as one of the most important oil-producing plants worldwide that has a high food value. Today, expansion of planting area of this plant has been highly considered. The presence of weeds in canola fields causes a significant loss in crop yield and quality. So far, the most widely herbicide used to manage weeds is the broad spectrum glyphosate that targets 5 enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme. In this study, with the aim of identification of new strategies to develop herbicides-resistant plants, Glyphosate Oxidoreductase (gox) and epsps genes under the control of CaMV 35S promoter were transferred to canola seedlings with pBI121 expression vector, to develop new plants with higher herbicide resistance level. Acquired seedlings were screened and then subjected to herbicide resistance bioassay. Molecular analysis of transgenic lines through PCR and RT-PCR showed successful integration and expression of the transgene, respectively. Result showed the higher relative resistance of the transgenic lines expressing two gene cassettes compared to single gene cassette lines. This study suggests that simultaneous application of two different strategies can lead to more glyphosate-resistance to develop new genetically modified crops specifically in oilseed plants such as canola.

Aims: In recent years, according the benefits of chloroplast transformation, the cultivation of transplastomic plants and their products have been increased. Due to their biosafety concerns, their identification and labeling have become more widely considered. The aim of this study was to present an optimal method based on polymerase chain reaction (PCR) and nanobiosensor for detection of transplastomic tobacco plants and compare their sensitivity. In the present experimental research, aadA gene as a chloroplast selectable marker was considered to design specific primer and probe. In PCR method, after optimization of aadA gene amplification, its sensitivity was evaluated with different percentages of transplastomic DNA. In nanobiosensor method at first, the labeled aadA probe was immobilized on graphene oxide (GO) and, then, hybridization reaction was optimized to identify target DNA sequence.
Findings: The amplification of 800 bp DNA related to aadA gene was observed. The PCR reaction allowed up to 5% DNA transplostomy tobacco to reproduce the aadA gene. In results of nanobiosensor after immobilization of aadA probe on GO, fluorescence emission was quenched and by adding the trasplastomic tobacco, DNA was observed again. In this method, up to 1% transplastomic tobacco DNA, fluorescence emission was significant in comparison with control tobacco plant. The PCR method can detect a transplastomic tobacco plant with 5% DNA sensitivity and detect biomarker sensitivity with 1% DNA sensitivity.
The PCR method can detect a transplastomic tobacco plant with 5% DNA sensitivity and nanobiosensor can detect with 1% DNA sensitivity. Therefore, nanobiosensor method is not only a reliable diagnostic method, in addition to the PCR method for detecting transplastomic plants, but also has a higher sensitivity.

Microbial communities are a key element of soil quality and fertility. This research aims to survey the effect of genetically modified cotton cultivar Coker, harbors an endochitinase gene (chi) from Phaseolus vulgaris (bean) on soil bacterial communities. The transgenic chi-resistant cotton (GM), line R8 was selfed for four generations and the corresponding original plant line 1011, wild-type (WT) were provided and planted in the transgenic greenhouse (Biosafety Level 2) at Agricultural Biotechnology Research Institute of Iran (ABRII). Samples of soil were collected from rhizosphere and bulk area of 30, 60 and 90 days old plants. Enumeration of total bacteria and Actinomycetes were carried out using TSA, Water Agar and ISP2 media. Soil DNA was extracted from 1-g samples by using an Ultra Clean soil DNA kit. PCR–DGGE (Denaturing Gradient Gel Electrophoresis) was performed to show diversity in different groups of bacteria. Total numbers of bacteria in soil samples was approximately 106 and 107 CFU/g of dried soil of rhizosphere and bulk soil respectively. Average number of total soil bacteria and Actinomycetes were higher in rhizosphere area of 30 and 60 days old GM plants compared to the control. Although, at the end of growth period (90 days) GM (transgenic) and non-GM plants were approximately equal in number of bacteria around their roots. Molecular analysis based on PCR-DGGE revealed similar microbial dynamics for both Actinomycetes and total batera. The data presented here showed no consistent statistically significant differences in the numbers of total bacteria and Actinomycetes between rhizosphere and bulk soil of chi and non-chi cotton at the end of the experiment. Furthermore, it seems that the growth stage of plant exerts a noticeable effect on the microbial community.

Transgenic crops (TCs) have potentially higher yield and quality as compared to their traditional relatives. Cultivation of these crops will lead to less use of chemical pesticides. In addition to its use as food resources, TCs “such as soybeans, canola, cotton, corn and potatoes” are currently being used for livestock feeding. About 90 percent of transgenic soybeans as well as 70 percent of transgenic corns have been assigned to the livestock sector so that, it can be said that TCs constitute a significant part of the fodder needed for livestock feeding. Researches have shown that chemical contents of transgenic crops are same as non-transgenic crops in terms of their chemical composition and amino acid content. Moreover, so far, no allergic property has been reported for TCs. Surveys have also shown that the compounds, digestibility, feed value and safety aspects of TCs were quite substantial equivalence with non-transgenic crops. The present study is an overview of concerns about the use of TCs for livestock feeding.

Biodiversity ensures the existence of every ecosystem. Among the levels of biodiversity, genetic diversity, as raw material for breeding, has gained more attention in agricultural societies, scope of which is considered as a durability index of productivity. Genetic resources constitute the foundation of modern agriculture and are necessary for attaining food security. The hazard of loss of genetic resources first came into the attention of scientists in middle of twentieth century, followed by universal implements to protect these valuable reservoirs. However, breeding methods per se restrict genetic base and cause genetic vulnerability against unfavorable environmental conditions and biotic stresses. On the other hand, high potential existing in genetic resources, as repository of precious characteristics, has remained unutilized. The advent of genetic engineering modified many concepts in various domains including genetic resources. Having the capacity to pass the limiting borders, this technology is promising to make concealed potential of genetic resources free and enhance germplasm. Genetic engineering targets and harnesses harmful pests, conserving the useful organisms. This technology has prevented the soil erosion through encouraging the farmers to adopt conservation agriculture methods in different countries leading to biodiversity conservation of the soil. Having in mind the valuable attainments of genetic engineering in food production and security and great revolution expected by this technology in future, it may be stated that human being has entered a new era of supplying his basic necessities.

Plants are considered as one of the world’s valuable genetic resources. It is expected that more than 15 to 40 percent of all living species will become extinct by the year 2050. Since 1960, studies were seriously raised over species going extinct as well as conservation of genetic resources leading to establishment of international organizations. These organizations have proposed some actions to protect endangered species such as, establishing of plant gene banks, determining protected areas for the conservation of genetic resources, and cultivation of becoming extinct plant species in the botanical gardens. Their works was mainly based on new procedures such as genetic engineering as a quick and efficient tool to save becoming extinct species. This technique allows identification and cloning genes responsible for resistance against biotic and abiotic stresses from different organisms and transferring the resistance resources into becoming extinct species to save them. The aim of this study was to investigate the role of transgenic plants in the conservation of becoming extinct species and increase of biodiversity.

Agrobacterium rhizogenes causes hairy root disease in plants. The hairy roots produced by A. rhizogenes infection are characterized by high growth rate and genetic stability. Hairy root induction cause changes in plant Secondary metabolites production. Phenolic compounds (Flavonoids, Tannins and Anthocyanins) are important antioxidants in radish. In this work, for induction of hairy roots, leaf explants transformed with two Arhizogenes strains (A4 and GUS). Generated Hairy roots confirmed with PCR. Also, Phenolic compounds content in hairy roots was measured. Amplification of 780bp fragment for rolB and 320bp for GUS in transgenic roots confirmed the production of hairy roots. Difference of Phenolic compounds between transgenic and non-transgenic roots was significant. Our results indicate that the insertion of A. rhizogenes T-DNA in to the plant genome stimulate plant defense responses and increase the production of Phenolic compounds.

The pollution with increased human activity and industrial development is increasing every day around the world. The pollution is generated by contaminants such as organic compounds and inorganic compounds containing heavy metals. There are various chemical and physical methods to remove these contaminants. But scientists due to high cost, incomplete removal of contaminants, environmental destruction and erosion by these methods, to study and development of biological techniques have made. A type of bioremediation methods is use of plants to clean up organic contaminants and minerals in water, soil and air. The remediting is done through complex mechanisms in plants. Today, the science of genetic engineering by using the genes in plants with the potential to clean-up or accumulation, they can produce transgenic plants with resistance to higher concentrations of pollutants. In this paper, according to previous studies, mechanisms of plants in removing of various contaminants and genetic engineering advances in the production of transgenic plants with phytoremediation potential is revised.

Cultivating more than 170. 3 million hectares of GM products in more than 28 countries and consumption of GM products in hundreds of countries، do not block opposition of some apparently environmentalist or Human health groups. One of the concerns expressed by these groups is probability of unintended effects due to insertion of transgene in a region of host genome which may be critical to the quality of the product. Toevaluate theresult ofinsertionof a transgene into the genomeknowing the sequence surrounding the integrationsitecan be useful. Althoughthe Identification of DNA sequences flanking transgene insertions site is not consider as a necessary steps of biosafetyriskassessment، butGM productsmanufacturersandresearchers in thisfield do this analysis voluntary and to create more confidence in consumers. Various methodshave been proposedto determination of DNA sequences adjacent to transgene، each method has advantages and special complexities. This paper review and analysis the procedures. These techniquesincludemethodsbased cloning andPCR. Cloning despite high accuracy، less has been used due to time-consuming. In contrast، PCR-based methods are rapid and cheap and a large number of these methods have been developed in recent years،which are divided into three main groups: inverse PCR، ligation/adaptor mediated PCR and primer-based methods.

The application of the concept of pathogen derived resistance opened new horizons for the development of virus-resistant plants. In this mechanism، resistance to a virus is engineered in transgenic plants through the expression of a segment of the virus genome. This technique simply improves the development of crops which deliver high yields. On the other hand، there are some concerns about transgenic crops consumption. Also development in pesticides، chemical fertilizers and other technologies related to modern intensive agriculture threaten both human health and environment. Therefore the first step after transgenic plant production is to evaluate its potential benefits and risks to the environment and these should be compared to those generated by traditional agricultural practices. The main ecological concerns that are currently debated are complementation، heterologous encapsidation، synergy، plant-to-plant gene flow by outcrossing، plant-to-virus gene flow by recombination، effect on nontarget organisms، food and feed safety.