Biotic and Abiotic stress
Narjes Fatahi; Hamid Sobhanian; Khadijeh Razavi; Tahmineh Lohrasebi; Gholamreza BakhshiKhaniki
Abstract
Environmental stresses have an irreversible effect on the production of bread wheat (Triticum aestivum L.), one of the most important crop plants. On the other hand, AP2/ERF members are the most important transcriptional regulators that influence plant growth and response to biotic and abiotic stresses. ...
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Environmental stresses have an irreversible effect on the production of bread wheat (Triticum aestivum L.), one of the most important crop plants. On the other hand, AP2/ERF members are the most important transcriptional regulators that influence plant growth and response to biotic and abiotic stresses. To evaluate the mechanism of salt stress tolerance in wheat the activities of superoxide dismutase, ascorbate peroxidase and catalase in two tolerant wheat landraces (3623 and 3625) under salinity were investigated by completely randomized factorial experiment at control and 250 mM salinity in three replications. Seedlings were sampled at 0, 1, 3, 6, 12 and 24 h and 10 days after stress. The activity of enzymes was measured in the root and shoot of plants. The AP2-21 nucleotide sequence was extracted from the NCBI database and primers were designed and the gene fragment was isolated from wheat and then cloned and sequenced and confirmed by the presence of AP2 conserved domain. TaAP2-21 expression was evaluated by qPCR using specific primers and β-actin housekeeping genes. The results showed a significant difference in enzyme activity at different times compared to control in both tissues of both landraces and the highest was observed in short and medium-term stresses, however, apparently in long term stress the antioxidant mechanism of the enzymes is more active in 3623 than in 3625. Gene expression decreased significantly under salinity in both tissues. The TaAP2-21 gene is probably one of the inhibitors of the transcription of saline responsive genes and causes salt sensitivity in wheat.
Molecular farming
Seyed Javad Davarpanah; Majid Dana; Gholamreza Bakhshi Khaniki; Amir Abbas Mokhtarieh
Abstract
Laccases are a group of glycoproteins which can oxidize a wide range of compounds with various biological activities and industrial applications in food and beverage, pharmaceutical, textile, and even military-related industries. Regarding this enzyme structure and the ability of plant protein production ...
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Laccases are a group of glycoproteins which can oxidize a wide range of compounds with various biological activities and industrial applications in food and beverage, pharmaceutical, textile, and even military-related industries. Regarding this enzyme structure and the ability of plant protein production machinery for protein glycosylation, a construct consisting of fungal laccaseII under control of root-specific mannopine synthase promoter and tobacco etch virus translation enhancer was designed for tobacco transformation to be used in phytoremediation. N-terminal addition of acidic tobacco endochitinase Q to Laccase directs its apoplastic secretion. Putative laccase agrobacterium-mediated transformants were confirmed using polymerase chain reaction. Semi-quantitative PCR of roots and leaves of putative transformants showed differential expression of the laccase gene at the transcriptomic level resulting from the differential function of bacterial mannopine synthase promoter. Western blotting results confirmed production of mature protein in roots which also confirms the correct function of signal peptide and secretion of this enzyme into the apoplastic space of roots. Regarding their application for protein production or phytoremediation transgenics of interest should be screened based on protein concentration and enzyme activity.
Proteomics
Mehdi Ghaffari; Saadat Sharifi; Gholamreza Bakhshi Khaniki
Volume 8, Issue 22 , September 2018, , Pages 15-26
Abstract
In order to understand of the molecular mechanisms of drought tolerance in sunflower, proteomic pattern of roots in two drought sensitive and drought-tolerant lines were evaluated under limited and favorable water conditions. After 2DE and comparison of relative abundance of protein spots using t test, ...
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In order to understand of the molecular mechanisms of drought tolerance in sunflower, proteomic pattern of roots in two drought sensitive and drought-tolerant lines were evaluated under limited and favorable water conditions. After 2DE and comparison of relative abundance of protein spots using t test, 12 of 417 protein spots in sensitive and 17 of 467 in tolerant line were affected by drought stress significantly. Following nano-LC MS/MS the protein spots were identified using Mascot search engine in NCBI protein database considering more than 10 % sequence coverage and score of above 80. Cytoplasmic and nuclear proteins were the most proteins which were affected by water deficiency. Three protein spots i.e. Enolase, Glyceraldehyde 3-phosphate dehydrogenase and Chalcone synthase were expressed differentially in these lines. Reduction of Enolase as a sign of metabolic impairment could be resulted in downstream process under drought stress. Increased expression of Glyceraldehyde 3-phosphate dehydrogenase and Chalcone synthase could have a role in detoxification/removal of oxidative destruction and antioxidant capability of the tolerant line. Increased level of heat shock protein, dihydroflavonol reductase, Seed linoleate 9S-lipoxygenase, Ubiquitin carboxyl-terminal hydrolase and G protein indicated crucial role of defensive, protective and transductive process in reduction of drought injuries.
Tissue culture and Micropropagation
Keyghobad Kaikavoosi; Altaf Hosseini Nadaf; Gholamreza Bakhshi khaniki
Volume 5, Issue 9 , June 2015, , Pages 29-38
Abstract
In most transformation studies it has been indicated that adding proline to the tissue culture medium can increase the callus induction frequency and reduce induction time. Adding proline to callus induction medium in this phase can affect the production of aromatic compounds in rice and if the goal ...
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In most transformation studies it has been indicated that adding proline to the tissue culture medium can increase the callus induction frequency and reduce induction time. Adding proline to callus induction medium in this phase can affect the production of aromatic compounds in rice and if the goal of exogenous gene transformation is increasing the rice aromatic associated secondary metabolites such as 2-acetyl-1-pyrroline (2AP), this amino acid can slipup the final results. Although, absence of amino acids such as proline can reduce callus induction percentage. In this research, callus induction from two indica rice varieties; Ambemohar 157 and Indrayani were optimized, using MS medium having various concentrations of 2,4-D, without using proline. The results revealed that 2.5 mgl-1 of 2,4-D for Ambemohar 157 and 4 mgl-1 for Indrayani can lead to better callus induction. These results indicated that absence of proline can be disregard by increasing of 2,4-D concentrations. Calluses obtained from the best hormone treatment were cultured on MS fortified with 0.01 mgl-1 NAA + (1, 2, 3, 4, 5) mgl-1 BAP for shoot regeneration. The highest percentage of regeneration was achieved on MS supplemented with 2 mgl-1and 3 mgl-1 for Ambemohar157 and Indrayani cultivar respectively. Proline contents in calli which were growth in MS medium supplemented with 500 mg/L of proline showed approximately 12 to 14 fold increase over the calli growth in non-proline added medium.
