Genetic engineering & plant breeding
Mohammad Sadegh Taghizadeh; Mohammad Mehdi Sohani; Reaz Shirzadian-Khoramabad
Abstract
Only a few low molecular weight signals, including jasmonic acid (JA), salicylic acid (SA), and ethylene (ET), regulate the expression of a group of defense-related genes in the plants. The expression of plant defense genes is stopped against aggressive agents using these regulators, and in some cases, ...
Read More
Only a few low molecular weight signals, including jasmonic acid (JA), salicylic acid (SA), and ethylene (ET), regulate the expression of a group of defense-related genes in the plants. The expression of plant defense genes is stopped against aggressive agents using these regulators, and in some cases, may be able to destroy or strengthen the defense signaling pathways of the plant for their purposes. In this study, the acetosyringone was used to study virulence genes induction in Agrobacterium tumefaciens A348 (MX311) and A348 (MX243) at three levels of 0, 100, and 200 μM. Subsequently, a concentration of this, which induced virulence genes highly, was selected to transform the Arabidopsis mutants using Agrobacterium tumefaciens EHA105. The results showed that the highest expression of virD2 and virB2 was at the levels of 200 and 0 μM of acetosyringone, respectively. Besides, the transformation results showed that the highest and lowest transformation efficiency was in the SA mutants (nahG) and the control plants (Col-0), respectively. Therefore, since the SA-suppression mutants have the highest transformation efficiency compared to others, it can be concluded that the SA may play more role in plant defense against pathogens than two other hormones. Hence, increasing the efficiency of gene transfer in these mutants will open the way for the expression and production of higher amounts of recombinant protein in these mutants compared to the wild type.
Genetic engineering & plant breeding
Mahmood Khosrowshahli; Elham Ansari; Ali Ashraf Jafari; Ali Etminan
Abstract
The comet assay is a sensitive test for detecting DNA damages used as an instrument to compare the intensity of the genotoxic effects of colchicine. The Pattern and the index value of three parameters of comet assay (tail length, tail intensity, tail moment) were compared among the autotetraploids produced ...
Read More
The comet assay is a sensitive test for detecting DNA damages used as an instrument to compare the intensity of the genotoxic effects of colchicine. The Pattern and the index value of three parameters of comet assay (tail length, tail intensity, tail moment) were compared among the autotetraploids produced from three populations of diploid cross pollinated Medicago sativa spp. Caerulea and autotetraploid populations from five diploid self pollinated species by treatment with three concentrations of colchicine (0.1, 0.5, and 1%) and five alfalfa cultivars. Results have shown the same level of increases and pattern in the parameters of comet "among the induced tetraploids from the two categories of medics" in the concentration of 0.1 and 0.5% of colchicine. Also increasing colchicine concentration from 0.1 to 0.5% resulted in a more pronounced augmentation of comet parameters. Induced tetraploids resulted from the two mentioned colchicine concentrations showed increases in the value of the three comet parameters compared to the cultivated alfalfa cultivars and two diploid categories medic species so the pattern of parameters were not similar. At the concentration of 1% of colchicine, only two annual species produced tetraploids showing very pronounced augmentation of comet parameters in comparison with 0.1 and 0.5% colchicine concentrations. Changes in patterns and values of the three parameters in induced tetraploids compared to cultivated alfalfa and diploid medic species demonstrate differential effects of damages of colchicine from one concentration to another, then a new variability in each concentration change will be created.
Genetic engineering & plant breeding
Morteza Noryan; Islam Majidi Harvan; hossein sabouri; Farokh Darvish Kojouri
Abstract
To evaluation of the genetic structure of drought tolerance in rice, an experiment was conducted using 120 RILs in a randomized complete block design with three replications in Gonbad Kavous University. 16 and 20 QTLs were identified at vegetative and reproductive stages, respectively. The correlation ...
Read More
To evaluation of the genetic structure of drought tolerance in rice, an experiment was conducted using 120 RILs in a randomized complete block design with three replications in Gonbad Kavous University. 16 and 20 QTLs were identified at vegetative and reproductive stages, respectively. The correlation variance analysis results indicated a significant relationship between traits under normal and drought stress conditions at the two growth stages. At the vegetative stage, this significant difference was recorded in all studies traits, except for plant height, at the 1% level, suggesting the diversity of the analyzed lines for the measured traits. In a comparison of the three evaluated treatments, the qRN-12, qRS-11, and qRV-12 lines were determined as stable QTLs appropriate for a selection of drought-tolerant and drought-sensitive lines at the vegetative stage in different conditions. At the reproductive stage, the highest correlation coefficient was obtained in the panicle length from the comparison of traits in flooded and drought stress conditions. Several new alleles of drought-tolerant QTLs identified in this study. In two environmental conditions, the important detected QTLs, such as qNTF-12 and qNL-3, belonged to the numbers of fertile tillers and leaves, determined as stable QTLs at the reproductive stage. Most of the traits were identified on the rice chromosome 12 and its genomic regions. In this study, the QTLs identified at vegetative and reproductive stages can be used as stable and major QTLs for the selection of drought-tolerant and drought-sensitive lines at all plant growth stages using marker-assisted selection in the rice.
Genetic engineering & plant breeding
Mehdi Arefrad; Ghorban Ali Nematzadeh; Mozhdeh Arab; Ali Raei; Fatemeh Avakh; Fatemeh Aliakbari; morteza oladi; Ammar Afkhami; Elham Younesi-Melerdi; Faeze Vadipour
Abstract
Although plant breeding has been able to increase rice yield, the quality of cooking and eating quality is still one of the most important economic factors in rice production. In order to better understand the genetic relationships between quantitative and qualitative properties, the most important agronomic ...
Read More
Although plant breeding has been able to increase rice yield, the quality of cooking and eating quality is still one of the most important economic factors in rice production. In order to better understand the genetic relationships between quantitative and qualitative properties, the most important agronomic traits, physicochemical properties and storage protein characteristics in two new mutant cultivars of rice, their parents and ancestors were evaluated. The results of agronomic traits showed that two mutant cultivars Roshan and Shahriar, have the highest yield (8500 and 8000 kg/ha respectively) accompanied by desirable agronomic characteristics such as lodging resistance, early maturity period, high number of tillers and more panicle length. Evaluation of qualitative properties also showed that these two new mutant cultivars characterized by good cooking and eating properties. As Roshan, show moderate amylose content (AC) and both of them were in terms of gelatinization temperature (GT) and gel consistency (GC) similar to Sangetarom, a quality cultivar. Also, Roshan cultivar, like Sangetarom, was differentiated by the recessive allele of BADH2 gene for fragrance. On the other hand, Shahriar cultivar also showed a significant decrease for prolamin protein. In general, the results show that there is no significant relationship between agronomic characteristics and yield with grain biochemical properties, such as cooking and eating quality, fragrance and storage protein content. These results promise that by identifying and pyramiding desirable alleles, especially alleles involved in starch synthesis, fragrance and prolamin protein can be obtained rice cultivars with higher qualitative properties.
Genetic engineering & plant breeding
Masumeh Dezhabad; Hengameh Taheri; Babak Pakdaman Sardrood
Abstract
Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. lycopersici (FOL) is one of the major devastating diseases of tomato plants throughout the world. There is no information on the molecular response of tomato line, Early Urbana-Y to FOL. The present study was performed to study the line response ...
Read More
Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. lycopersici (FOL) is one of the major devastating diseases of tomato plants throughout the world. There is no information on the molecular response of tomato line, Early Urbana-Y to FOL. The present study was performed to study the line response to FOL using phytopathological (disease severity and shoot fresh weight) as well as molecular methodologies. The transcription of several genes responsive to jasmonic acid (JA; Pin2), salicylic acid (SA; Chi3, Chi9 and PR1), the regulatory genes responsive to the signaling hormone JA (MYC2 and WRKY33) and ethylene (ET; ERF1) were studied by qRT-PCR technique at different time points after FOL inoculation (6-96 hour after inoculation). Disease symptoms development and reduced shoot fresh weight of the inoculated plants despite up-regulation of SA-dependent defense genes at different time points after pathogen infection indicated that SA signaling pathway is involved in the susceptibility of the Early Urbana-Y line to FOL. In contrast, JA and ET pathway genes were not strongly induced in response to the pathogen suggesting the involvement of JA/ET-mediated defense responses in reducing disease susceptibility. However, to gain a better understanding of enhanced resistance to fusarium wilt, more detailed molecular mechanisms underlying susceptibility of Early Urbana-Y line to FOL need to be further investigated in the future.
Genetic engineering & plant breeding
Mohammad Majidi; Yones Bahmani
Abstract
Isolation of high-quality RNA is one of the most crucial methods in molecular biology. RNA extraction from woody plants has been problematic due to the presence of rigid and woody tissues, large amounts of polysaccharides, polyphenols and other secondary metabolites. Here we present a suitable protocol ...
Read More
Isolation of high-quality RNA is one of the most crucial methods in molecular biology. RNA extraction from woody plants has been problematic due to the presence of rigid and woody tissues, large amounts of polysaccharides, polyphenols and other secondary metabolites. Here we present a suitable protocol for RNA isolation from a wide range of woody plants that includes eight gymnosperms and four angiosperms. The method is based on the CTAB protocol which was modified by adding sodium citrate and two helper buffers. Agarose gel electrophoresis showed a good RNA integrity and total RNA profile that includes all expected RNA bands. Also, DNA and protein contaminations were not observed. Spectrophotometric quantification of RNA samples by NanoDrop showed that the average RNA yields ranged from 35.68 to 216.98 µg per gram fresh weight, that is enough to proceed into cDNA synthesis and other RNA-related works. Both the A260/A280 and A260/A230 ratios were in the desired ranges, indicating that RNA was of high purity and without protein, polyphenol, and polysaccharide contamination. The efficiency of isolated RNA for downstream applications was verified by real-time PCR and successful amplification of a long cDNA. Finally, some advantages and possible applications of the method are also mentioned.
Genetic engineering & plant breeding
Azadeh Mohseni; Ghorban Ali Nematzadeh; Ali Dehestani; Behzad Shahin; Elham Soleimani
Abstract
Plants are naturally exposed to frequent changes in environmental conditions such as salt stress affecting their growth and development, and consequently a considerable reduction in total productivity. Monodehydroascorbate reductase (MDHAR), a key enzyme in ascorbate-glutathione cycle, serves as an important ...
Read More
Plants are naturally exposed to frequent changes in environmental conditions such as salt stress affecting their growth and development, and consequently a considerable reduction in total productivity. Monodehydroascorbate reductase (MDHAR), a key enzyme in ascorbate-glutathione cycle, serves as an important antioxidative enzyme in scavenging of reactive oxygen spices (ROS). In this study, MDHAR gene from Aeluropus littoralis was isolated using specific primers by RT-PCR and its expression variation was investigated at 0, 150, 300, 450 and 600 mM of NaCl through Real-time PCR. The results indicated that A. littoralis MDHAR gene compromised 1436 bp without any introns, showing a high similarity with Sorghum bicolor. The only alteration of MDHAR expression was observed at 300 mM NaCl, i.e. cytosolic MDHAR in both shoot and root was increased 1.3 and 1.4 fold compared to control samples. It could be concluded that accumulation of MDHAR reduces at Nacl concentrations higher than 300 mM.
Genetic engineering & plant breeding
Milad Alizadeh; Hoseein Askari
Abstract
The plant-pathogen interaction is a multifactor process that may lead to resistance or susceptible responses of plant to pathogens. During the arms race between plant and pathogens, various biochemical, molecular and physiological events are triggered in plant cells such as ROS signaling, hormone activation ...
Read More
The plant-pathogen interaction is a multifactor process that may lead to resistance or susceptible responses of plant to pathogens. During the arms race between plant and pathogens, various biochemical, molecular and physiological events are triggered in plant cells such as ROS signaling, hormone activation and gene expression reprogramming. In plants, microRNAs (miRNAs) are key post-transcriptional regulators of gene expression and are involved in several cellular processes including response to environmental stress. In recent years, plant pathologists have presented a logical approach of plant immune system as zigzag based model that includes two phases of immunity, PTI and ETI in which miRNA molecules are determinant regulators. Here, we present an overview of miRNA biology, a brief explanation of plant immune systems in zigzag model, the role of phytohormones and miRNAs in plant immunity with a main focus on Arabidopsis-Pseudomonas interactions and finally we discuss our results on miRNA expression in lemon-Xanthomonas interactions.
Genetic engineering & plant breeding
Mohammadali Malboobi
Abstract
World population has already exceeded 6.5 billion, out of which about 850 million (13 percent) are undernourished. With the current growth rate, the world community faces even a greater challenge of hunger and food security as the estimated the population will catch 9 billion by the year 2050 with doubled ...
Read More
World population has already exceeded 6.5 billion, out of which about 850 million (13 percent) are undernourished. With the current growth rate, the world community faces even a greater challenge of hunger and food security as the estimated the population will catch 9 billion by the year 2050 with doubled needs for food. At the same time, preservation of biodiversity, stopping deforestation and reduced environmental footprint caused by agricultural practice are the main concerns towards sustainable agriculture. The progressive adoption of genetically modified organisms (GMOs) including GM crops and trees can make a decisive contribution to improve harvest and alleviate hunger and poverty. In addition to the environmental benefits, the introduced GMOs can improve water use efficiency and reduce the need for fossil based fuels and pesticide application and reduce thousands of tons of emissions of green house gases. In this respect, several social issues are still of concern. On one hand, many beneficial advantages of GMOs have encouraged a wide spectrum of large or small farmers to cultivate transgenic plants which is translated to food security and job opportunities. On the other hand, while ideological debates have hindered, or even ceased, technology provisions in developing and underdeveloped countries, GMO seed and food productions are monopolized by a quite small number of transnational companies. For instance, seeds that were previously available at low or no cost, mainly through public institutes, international entities or seed exchange among farmers, would be offered at higher prices due to exclusive right of producers and additional cost of patent royalties. Cartagena protocol is going to regulate the relationship among countries aiming at preservation of world biodiversity. Although the developing countries outnumbered developed nations that cultivate transgenic plants in recent years, current statistic shows that around 84 percent of GMO crops are cultivated by only four countries, USA, Brazil, Argentina and Canada. Scientist and scholars, particularly in Islamic states, as well as decision makers are the major responsible bodies that must take roles for the current and future situations. Despite the fact that most of scientists or scholars are not in navigation positions, however, they can discuss socio-economic issues and raise public awareness in order to harmonize their efforts towards proper utilization of biotech products in their society and towards a reliable point for food security and safety.
Genetic engineering & plant breeding
Ebrahim Doranie Uliaie; Behzad Ghareyazi; Mohammad Farsi; Karl-Heinz Kogel
Abstract
A significant portion of the world’s cultivated land is affected by salinity that reduces crop productivity in these areas. Breeding for salt tolerance is one of the important strategies to overcome this problem. Recently, genetic engineering is becoming a promising approach to improving salt tolerance. ...
Read More
A significant portion of the world’s cultivated land is affected by salinity that reduces crop productivity in these areas. Breeding for salt tolerance is one of the important strategies to overcome this problem. Recently, genetic engineering is becoming a promising approach to improving salt tolerance. In order to improve the yield performance of canola in saline soils, we transformed canola with Arabidopsis vacuolar Na+/H+ antiporter gene AtNHX1 which enhances the plant capacity for reducing cytosolic Na+ by transporting Na+ into the vacuole. Southern analysis of putative transgenic plants indicated that only one copy of the gene integrated into the plant genome. Overexpression of the AtNHX1 gene was shown in T1 transgenic plants. Under salinity conditions, stem and root length and overall biomass of transgenic plants were significantly higher compared to those of nontransgenic plants. Moreover, salt treated transgenic plants contained high proline and K+, but less Na+ compared to wild type.