Biological Effects of Weak Electromagnetic Field on Healthy and Infected Lime (Citrus aurantifolia) Trees with Phytoplasma

Exposure to electromagnetic fields (EMF) has become an issue of concern for a great many people and is an active area of research. Phytoplasmas, also known as mycoplasma-like organisms, are wall-less prokaryotes that are pathogens of many plant species throughout the world. Effects of electromagnetic fields on the changes of lipid peroxidation, content of H2O2, proline, protein, and carbohydrates were investigated in leaves of two-year-old trees of lime (Citrus aurantifolia) infected by the Candidatus Phytoplasma aurantifoliae. The healthy and infected plants were discontinuously exposed to a 10 KHz quadratic EMF with maximum power of 9 W for 5 days, each 5 h, at 25°C. Fresh and dry weight of leaves, content of MDA, proline, and protein increased in both healthy and infected plants under electromagnetic fields, compared with those of the control plants. Electromagnetic fields decreased hydrogen peroxide and carbohydrates content in both healthy and infected plants compared to those of the controls

A comparative study on the effects of ultrasound and some growth factors on somatic embryogenesis and artificial seed production in cucumber (Cucumis sativus L.)

Cucumber (Cucumis sativus L.), a popular vegetable crop of the family Cucurbitaceae, is cultivated in different parts of the world and is of great economic importance. Ultrasound is known as a physical stimulus that can affect living systems. At the right frequency and exposure period, these waves have desired effects. In the present study, 2-week-old plants, were put in an ultrasonic bath with a nominal frequency of 40 kHz, a central frequency of 34/722 kHz and a bandwidth of 320 Hz for 0, 5, 10 and 15 minutes. Hypocotyl pieces were used as explants and cultured in Murashige and Skoog medium supplemented with 0/5 mg/l each of 2,4-dichlorophenoxyacetic acid, 1-Naphthalene acetic acid, kinetin and 6-benzylaminopurine. The use of ultrasonication at a nominal frequency of 40 kHz for 10 minutes showed better results as compared with the samples treated for 0, 5 and 15 minutes, in terms of the shape, maturity of the embryos, and also the germination of artificial seeds and maturing to flowering stage. Since the cucumber of Esfahan is very famous for its aroma and taste and it is somewhat at risk of extinction, we studied the production of artificial seeds of this valuable plant using somatic embryos and apical buds. This research is the first report on investigation of the positive effect of ultrasound on somatic embryogenesis and artificial seed production. our results clearly showed that this method is a practical method to accelerate seed germination and flowering stage

Optimization of the fermentation media, mathematical modeling, and enhancement of paclitaxel production by Alternaria alternata after elicitation with pectin

Alternaria alternata fungus is a potent paclitaxel producer isolated from Corylus avellana. Themajor challenge is the lack of optimized media for endophytic fungi productivity. In the effort tomaximize the production of taxoids by A. alternata, several fermentation conditions, including pH(pH 4.0–7.0), different types and concentrations of carbon (fructose, glucose, sucrose, mannitol,sorbitol, and malt extract), and nitrogen (urea, ammonium nitrate, potassium nitrate, ammoniumphosphate, and ammonium sulfate) were applied step by step. Based on the results, A. alternata in amedium containing sucrose 5% (w/v) and ammonium phosphate 2.5 mM at pH 6.0 showed a rapid andsustainable growth rate, the highest paclitaxel yield (94.8 μg gFW−1 vs 2.8 μg gFW− 1 in controls), andthe maximum content of amino acids. Additionally, the effect of pectin was evaluated on fungus, andmycelia harvested. Pectin significantly enhanced the growth and taxoid yield on day 21 (respectively171% and 116% of their corresponding on day 7). The results were checked out by mathematicalmodeling as well. Accordingly, these findings suggest a low-cost, eco-friendly, and easy-to-produceapproach with excellent biotechnological potential for the industrial manufacture of taxoids.</p

Developed network between taxoid and phenylpropanoid pathways in Cryptosporiopsis tarraconensis, taxan-producing endophytic fungus by Debiased Sparse Partial Correlation (DSPC) algorithm.

Although bioproduction of Paclitaxel by endophytic fungi is highly considered as an alternative promising source, but its yield is usually very low in comparison with other taxoids. Different strategies i.e., chemical and physical elicitations have been developed in order to overcome the shortage of Paclitaxel production. Paclitaxel biosynthesis is started with terpenoid pathway followed by phenylpropanoid metabolism where a benzoylphenylisoserine moiety is attached to C13 of baccatin III skeleton. This point which is catalyzed by the function of PAM seems to be a bottleneck that limits the rate of Paclitaxel production. Whether phenylpropanoids pathway regulates the taxanes biosynthesis in Cryptosporiopsis tarraconensis endophytic fungus elicited with benzoic acid (BA) was hypothesized in the present paper. The involvement of certain signal molecules and key enzymes of terpenoid and phenylpropanoid metabolism were investigated. According to the results, application of BA promoted a signaling pathway which was started with increase of H2O2 and ABA and continued by increase of NO and MJ, and finally resulted in increase of both phenylpropanoids and taxanes. However, again the rate of Paclitaxel production was lower than other taxoids, and the latter was much lower than phenolics. Therefore, supplying benzoic acid provided the precursor for the common taxan ring production. It is unlikely that Paclitaxel production is merely controlled by side chain production stage. It is more likely that in C. tarraconensis endophytic fungus, similar to Taxus sp., the competition between phenylpropanoid and taxoid pathways for substrate ended in favor of the former. The interaction network which was constructed based on DSPC algorithm confirmed that most compounds with close proximity have shared metabolic pathway relationships. Therefore, it is unlikely that the feeding with a given precursor directly result in increase of a desired metabolite which is composed of different merits

Developed network between taxoid and phenylpropanoid pathways in Cryptosporiopsis tarraconensis, taxan-producing endophytic fungus by Debiased Sparse Partial Correlation (DSPC) algorithm

Although bioproduction of Paclitaxel by endophytic fungi is highly considered as an alternative promising source, but its yield is usually very low in comparison with other taxoids. Different strategies i.e., chemical and physical elicitations have been developed in order to overcome the shortage of Paclitaxel production. Paclitaxel biosynthesis is started with terpenoid pathway followed by phenylpropanoid metabolism where a benzoylphenylisoserine moiety is attached to C13 of baccatin III skeleton. This point which is catalyzed by the function of PAM seems to be a bottleneck that limits the rate of Paclitaxel production. Whether phenylpropanoids pathway regulates the taxanes biosynthesis in Cryptosporiopsis tarraconensis endophytic fungus elicited with benzoic acid (BA) was hypothesized in the present paper. The involvement of certain signal molecules and key enzymes of terpenoid and phenylpropanoid metabolism were investigated. According to the results, application of BA promoted a signaling pathway which was started with increase of H2O2 and ABA and continued by increase of NO and MJ, and finally resulted in increase of both phenylpropanoids and taxanes. However, again the rate of Paclitaxel production was lower than other taxoids, and the latter was much lower than phenolics. Therefore, supplying benzoic acid provided the precursor for the common taxan ring production. It is unlikely that Paclitaxel production is merely controlled by side chain production stage. It is more likely that in C. tarraconensis endophytic fungus, similar to Taxus sp., the competition between phenylpropanoid and taxoid pathways for substrate ended in favor of the former. The interaction network which was constructed based on DSPC algorithm confirmed that most compounds with close proximity have shared metabolic pathway relationships. Therefore, it is unlikely that the feeding with a given precursor directly result in increase of a desired metabolite which is composed of different merits

Antioxidant Activity, Total Phenolics and Taxol Contents Response of Hazel (Corylus avellana L.) Cells to Benzoic Acid and Cinnamic Acid

Hazel (Corylus avellana L.) plant has been recently introduced as a plant with the ability to produce Taxol. In the present research effects of different concentrations of benzoic acid and cinnamic acid on the phenolic compounds, Taxol content, and antioxidant activity of extracts of suspension-cultured hazel cells were investigated. The cells were treated with different concentrations of benzoic acid (0, 0.5, and 1 mM) and cinnamic acid (0, 0.15, 0.3 and 0.6 mM) on day 7 of subculture and were harvested on day 14. Benzoic acid in higher concentrations increased Taxol (4 fold of the control) and antioxidant activity of the cell extract. Cinnamic acid supply did not bring remarkable increase in Taxol content but increased phenolic contents and antioxidant activity of hazel cells extract. Interestingly, the extract of hazel cells showed more cytotoxicity for human cancer cells than pure Taxol. Further investigations may suggest the extract of cinnamic- and benzoic acid- fed hazel cells for treatment of cancer cells

Antioxidant Activity, Total Phenolics and Taxol Contents Response of Hazel (Corylus avellana L.) Cells to Benzoic Acid and Cinnamic Acid

Hazel (Corylus avellana L.) plant has been recently introduced as a plant with the ability to produce Taxol. In the present research effects of different concentrations of benzoic acid and cinnamic acid on the phenolic compounds, Taxol content, and antioxidant activity of extracts of suspension-cultured hazel cells were investigated. The cells were treated with different concentrations of benzoic acid (0, 0.5, and 1 mM) and cinnamic acid (0, 0.15, 0.3 and 0.6 mM) on day 7 of subculture and were harvested on day 14. Benzoic acid in higher concentrations increased Taxol (4 fold of the control) and antioxidant activity of the cell extract. Cinnamic acid supply did not bring remarkable increase in Taxol content but increased phenolic contents and antioxidant activity of hazel cells extract. Interestingly, the extract of hazel cells showed more cytotoxicity for human cancer cells than pure Taxol. Further investigations may suggest the extract of cinnamic- and benzoic acid- fed hazel cells for treatment of cancer cells

Aluminum Affects the Antioxidant Activity of Tobacco Cells and the Expression of Salicylate-Induced Protein Kinase (SIPK)

It has been shown that Aluminum (Al) toxicity results in over-production of reactive oxygen species (ROS). Despite the fact that ROS can induce MAPK activation, no direct genetic evidence has linked ROS-induced MAPK activation with Al toxicity. The effect of Al on the activation of antioxidant systems in connection with the expression of salicylate-induced protein kinase (SIPK), was examined in tobacco cells. Suspension-cultured tobacco cells (Nicotiana tabacum L. cv. ‘Barley 21’) were treated with or without 80 μM Al. Certain parameters related to antioxidant activity were measured. A MAPKK inhibitor (PD98059) was also applied together with or without Al treatments and semi quantitative RT-PCR was applied to show the expression level of the SIPK gene. Treatment with Al rapidly increased the radical scavenging capacity of cells, catalase and superoxide dismutase activities, and expression of the SIPK gene, as compared to the control cells. In the presence of Al + PD98059, a decrease in catalase and superoxide dismutase activities was observed, compared to those cells which were treated only with Al. These results suggested that a short treatment with Al induced the activity of certain antioxidant enzymes in tobacco cells and that this response was mediated by a MAPK signal transduction pathway