جستجوی مقالات مرتبط با کلیدواژه "کیتوزان" در نشریات گروه "بیوتکنولوژی و ژنتیک گیاهی"

Salinity is one of the most important stresses that reduce the yield of most plants. Plants use different mechanisms in response to environmental stresses. Chitosan and its oligomers are used in plants to resist abiotic stresses such as salinity. In this study, the effect of chitosan and salinity on gene expression and p5cs enzyme activity and proline content in rapeseed was investigated.

For this purpose, rapeseed plants were treated with sodium chloride solution (0, 50, 100 and 150 mM) and chitosan (0, 5 and 10 mg/l). The experiment was performed as a factorial experiment with a completely randomized design in 3 replications. Treated plants were harvested to measure gene expression, p5cs enzyme activity and proline content.

With increasing salt concentration, the expression of delta-1 proline-5 carboxylate synthetase (P5CS) gene, enzyme activity and proline content increased. In the combined salinity of 100 mM with chitosan 10 mg/l, gene expression, activity and proline content in rapeseed had the highest amount. The use of chitosan in salt-containing medium compared to salinity treatments in same concentration, caused more P5CS gene to be expressed, increased enzyme activity and subsequently more proline was synthesized. Therefore, there is a positive correlation between gene expression, enzyme activity and the amount of proline produced.

According to the results, chitosan with a concentration of 10 mg / l in salinity treatment, by increasing gene expression and the activity of the enzyme delta-1-proline-5-carboxylate synthetase (P5CS), produced proline, which increases the plant's resistance to salinity stress.

Di-acetylated chitin derivative of is Chitosan that there is a biologically degradable cationic polymers; This natural polymer in the past to recover heavy metals from sea water and industrial water and diesel oil were used. Present of Metals in the oil is importance because of their impact. Some metals, such as copper and nickel as the catalyst and reducing oxidative reactions are known thermal stability of oil and therefore very little oil concentration of these metals can tolerate. The purpose of this research was to investigate the removal of heavy metals, iron and copper from soybean oil use to Commercial chitosan and is Best of Chitosan concentration and the reaction temperature. Removal of metals by adding Chitosan crude soybean oil at temperatures of 25, 45, 55, and 65 ° C act for 1 h and Measuring the atomic absorption efficiency of Chitosan most suitable reaction temperature and concentration were investigated. Removal efficiency is dependent on several factors such as the amount of chitosan , the temperature and time. The results of obtained can use to chitosan for the removal of heavy metals from edible oil and prevent oil degradation during production and storage According to its low cost relative to the types of adsorbents. According to the results, it was observed that increasing the chitosan concentration increased metal removal rates .

Glucoraphanine is an aliphatic glucosinolate, which largly found in Lepidium draba from Brassicaceae family. This glucosinolate convert to isothiocyanate, sulforaphane (SFN) in the presence of myrosinase which has different biological activities such as the antioxidant and anti bacterial properties, and also able to prevent proliferating of cancer cells.  CYP79F1 is the first enzyme in the biosynthesis pathway of glucoraphanine.

 In this study, L. draba seedlings wer grown for 7 days in the presence of different concentration of sucrose and chitosan (0, 25, 50, 100, 200 and 400 mg/L), in fully-random designs with three repetitions. After collection of the seedlings, SFN content in the arial parts of them were measured using HPLC apparatus. Furthermore, in the treated seedlings, the gene expression level of CYP79F1 were examined using the Real Time PCR technique.

 The results showed, that SFN content in the sucrose treated seedlings significantly increased compared to the control. While in the chitosan treated seedlings significant increase in SFN content was only seen at the 200 mg/L concentration. The results showed that the expression of CYP79 F1 was significantly increased in the treated seedlings with 50 mg/L sucrose and 50 and 100 mg/L chitosan compared to the control.

 According to the results, it concluded that the mentioned elicitor's concentrations can stimulate aliphatic glucosinolate biosynthesis through expression of CYP79F1 gene. Based on the role of SFN as a valuable medicinal metabolit and also the role of CYP79F1 enzyme in the glucoraphanin biosynthesis, it suggested that the effects of others concentrations and time of treatment of the mentioned elicitors were analyzed on this plant.

Hypericum perforatum has many medicinal properties such as anti-inflammatory, anti-bacterial, anti-viral and anti-tumor; but has been reported its greatest effect on the treatment of depression which is attributed to Hyperforin and Hypericin conjugates. The aim of this study was to evaluate the effect of chitosan (0, 50, 100 and 200 ppm) and silver nanoparticles (0, 30, 60 and 90 ppm) on expression of Hyp-1 gene. For this purpose, a real-time PCR experiment was carried out in a completely randomized design with three replications in two time period such as 48 and 72 hour. The results of analysis of variance were showed that interaction of silver nanoparticles, chitosan and time period was significant on the expression of Hypericin gene (P <0.01), so that the highest expression of Hyp-1 gene was obtained from 50 ppm chitosan with no silver nanoparticles in the period time of 48 hours. Overall, the results of this study showed that silver nano particles had a negative effect on Hyp-1 gene expression, and with increasing concentration of silver nanoparticles, the expression of Hyp-1 gene decreased. However, chitosan had a positive effect on Hyp-1 gene expression, but by increasing the concentration to 200 ppm, the amount of gene expression decreased.

The elicitors are biotic and abiotic compounds that by stimulation of defensive responses causes biosynthesis and accumulation of secondary metabolites. In this research, the expression of KO, UGT85C2, UGT74G1 and UGT76G1 genes involve in production pathway of steviol glycosides in the Stevia rebaudiana were investigated under chitosan, yeast extract and methyl jasmonate as elicitors.
For this purpose, the stevia plants were treated by the elicitors in 3 concentrations of 20, 40 and 80 mg/L and then apical leaves were harvested after one month. The results showed that chitosan in the concentration of 20 (mg/L) significantly increased the expression of UGT85C2 and UGT76G1 genes compared to control plants (16 and 5%). Plus, Chitosan in the concentration of 40mg/l significantly increased the expression of UGT85C2 gene (14%). Methyl jasmonate 20mg/l caused the highest expression of KO gene, which increased by 13% in comparison with control plant. Also, the expression of UGT85C2 gene under the concentration of 20 methyl jasmonate showed a significant increase. According to the results, it was found that increasing the concentrations of chitosan and methyl jasmonate had a negative effect on gene expression profiles of steviol glycosides. Yeast extract in the concentration of 40mg/l significantly increased the expression of UGT85C2 and UGT76G1 genes, which showed 11 and 5% increase in expression, respectively. It was specified that concentration of 40mg/l compared to concentrations of 20 and 80mg/l of yeast extract had a better effect on gene expression enhancement. Hence, according to the results, it can be concluded that chitosan and methyl jasmonate at low concentrations and yeast extract in a moderate concentration can stimulate of the gene expression profiles that involved in the production of steviol glycosides, so increasing the amount of chemical compounds can be effective in the production of secondary metabolites in s. rebaudiana.

Chitin and chitosan are two very important biopolymer products that have so many usages in the high cost industries. Chitin Converts into chitosan via de-acetylation of chitin. It occurs by alkaline melting method in the absence of oxygen. Chemical structure change, severe environmental pollution and De-polymerization are of the major problems in producing high quality chitosan. In this study for conversion of chitin into chitosan fungus Aspergillus niger strains (ATHUM-10864), the generator of de-acetylases enzymes were used instead of chemicals. Chitosan quality was determined via elemental analysis infrared spectroscopy, X-ray tomography, molecular weight determination and estimation of crystallinity percent, color and molecular structure.The results showed 80±5% efficiency in the conversion of chitin into chitosan or de-acetylation degree of chitin. The gained chitosan contained of 44.4% carbon, 8.9% nitrogen, 2.7% hydrogen and 39.5% oxygen. The physical characteristics were as 94.5% Crystallinity and pale brown color. The chemical structure of per unit of chitosan was obtained as C6H12NO4. The results showed that replacing biological methods instead of chemicals was possible to access well quality products. It also eliminates the use of chemical materials such as concentrate sodium hydroxide that is damaging the environment.