Showing 7 results for Inducer
Volume 5, Issue 4 (12-2016)
Abstract
Botrytis fabae is one of the most important fungal pathogens attacking the leaves and the stem of faba bean Viciafaba L. and causes severe yield losses. This study was carried out to evaluate the effect of four chemical inducers (salicylic, citric, ascorbic and oxalic acids) and one fungicide (Carbendazim) against B. fabae in field and glasshouse conditions. Under field conditions for two seasons and glasshouse experiments, plants treated with salicylic acid showed substantial and significant decrease in the disease severity on the leaves and the stem compared with the control and the fungicide. Salicylic acid was highly effective and controlled the disease better than Carbendazim which provided only partial protection. In vitro, the inhibition of fungal growth was investigated and showed that salicylic acid was the best inhibitor of fungal growth (48%) followed by oxalic (39%), ascorbic (33%) and citric (10%) acids 6 days after incubation. An important increase of total phenols was recorded in treatment by salicylic acid in the healthy and infected leaves of faba bean 12, 24, 48, 72, 96 and 120 hours after inoculation. These promising results on the control of the main fungal disease damaging faba bean in Tunisia and other regions will have an important impact on faba bean production.
Volume 6, Issue 1 (3-2017)
Abstract
One of the effective plant disease management strategies is based on the employment of resistance inducers. In the present study, to assay, the effects of Salicylic acid (chemical inducer) and Piriformospora indica (biological inducer) on wheat powdery mildew (Blumeria graminnis f. sp. tritici), the expression rate of Non-expresser of pathogenesis-related genes1 (NPR1) genewas evaluated using qPCR. For this purpose, Falat and Tajan cultivars were selected as susceptible and resistant genotypes to powdery mildew, respectively. To evaluate the rate of gene expression, the P. indica colonized Falat along with mock plants were inoculated with Powdery mildew. In another experiment, Falat treated with SA and control plants were inoculated with Powdery mildew 48 h after treatment with SA. Gene expression was assayed in Falat compared with resistant cv. Tajan. Sampling was carried out at 0, 6, 12, 24 and 48 hours after infection. Comparisons of gene expression patterns showed that after infection, the expression levels of NPR1 increased in induced and non-induced Falat and Tajan cultivars. The maximum gene expression levels were observed at 24 hours post infection. But the expression levels of the gene at this timewere much higher in induced treatments compared with control. The current study showed that NPR1 can be involved in resistance strategy. Thus, using NPR1 gene as a desired gene in genetic engineering for increasing the potential of plant resistance to pathogens can be considered. Moreover, the high response of NPR1 gene in induced plants indicated that both SA and P. indica play a critical role in inducing resistance.
H Garshasbi, B Fakheri, H Jalili, M Rahaie Jahromi, N Mahdinezhad,
Volume 9, Issue 2 (4-2020)
Abstract
Astaxanthin is a precious material and has many favorites for human; it is extracted from some creatures such as Haematococcus lacustris. Researchers try to maximize the production of this material. In this research effects of linoleic acid (LA), TiO2 and SiO2 Nanoparticles (NPs) were investigated on astaxanthin production, and expression of two astaxanthin metabolic pathway genes (CRTO and CRTR). The microalgae was cultured in BBM medium for 19 days autographically. In 3rd day, treatments were added to the cultures and astaxanthin measured in 3 days respectively in logarithmic and stationary phases, also RNA was extracted, Real-time PCR applied and Gene expression investigated in 11th. 30 µM LA and TiO2 NPs (40 mg L-1) induced 3.4 and 1.5 times astaxanthin production compared to the control, furthermore, CRTO and CRTR under 30 µM LA and SiO2 NPs (40 mg L-1) treatments displayed the highest gene expression. It was demonstrated that special concentration of Linoleic acid and TiO2 NPs, as inducers, could be used for astaxanthin production; also, Linoleic acid has a direct relationship with astaxanthin production and CRTO´s gene expression in the microalgae.
Volume 9, Issue 4 (12-2018)
Abstract
Aims: One of the ways to reduce cholesterol is to use statins that prevent cholesterol synthesis. The statins are similar to mevalonate and act as a competitive inhibitor of HMG-CoA reductase enzyme. Lovastatin is the eminent derivate of the statins group, which is produced by many microorganisms. At commercial scale lovastatin is produced in submerged culture by Aspergillus terreus. The industrial production of this metabolite is carried out by Aspergillus turosus in liquid culture. The main aim of this research was to investigate the effect of spore age on lovastatin production at the inoculation stage; also, the impact of adding olive oil and tetracycline as inducers for lovastatin production were examined.
Materials and Methods: In the present experimental research, different suspensions from varying ages of spore were prepared and added to the medium of Aspergillus terreus ATCC 20542; lovastatin concentration also was measured by High Performance Liquid Chromatography (HPLC).
Findings: The utmost lovastatin was observed in inoculum with 85 days spore age and equal to 60 mg/l, which was approximately twice higher compared to when inoculated with 10 days spore age. The best concentration of spore inoculation was 0.5×107 spores/ml. Lovastatin production significantly increased when tetracycline and olive oil were used as inducers.
Conclusion: As the inoculated spore age increases, lovastatin and biomass production is increased. The lovastatin production is increases by more than 1.5 times while adding tetracycline and olive oil compared to date syrup alone.
Volume 14, Issue 6 (11-2012)
Abstract
Salinity is among important soil stresses adversely affecting the process of nitrogen (N) fixation in leguminous plants in different parts of the world. It has been indicated that salinity can inhibit the early stages of nodulation process between bacterium and the host plant including the exchange of signal molecules (nod gene inducers). There has not been any research regarding the effects of nod gene inducers on the growth of alfalfa inoculated with Sinorhizobium meliloti under saline conditions. A growth chamber experiment was conducted to determine the effects of pre-incubation of S. meliloti with effective inducers of nod genes Luteolin, Methyl jasmonate and Genistein on the growth and N-fixation of two different alfalfa (Medicago sativa L.) cultivars (Yazdi and Hamedani) under salt stress. Nod gene inducers increased alfalfa growth and N fixation under normal as well as under salt stressed conditions. Yazdi cultivar showed to be more tolerant to salinity than Hamedani with a higher growth rate and N fixation. Luteolin was the most effective nod gene inducer on plant growth and N fixation under normal and as well under salt stressed conditions. The results suggest that pre-incubation of S. meliloti with effective nod gene inducers can improve alfalfa growth and N fixation under salinity stress.
Volume 17, Issue 6 (11-2015)
Abstract
The fruit set rate and yield of pear are commonly low due to insufficient pollination, as the species is unattractive to honeybees. To improve honeybee foraging behavior for the pollination of Dangshan pear (Pyrus bretschneideri cv. dangshansuli), nine methods were used to attract bees. A control treatment of colonies was fed with normal sugar syrup, while six other treatments were fed using sugar syrup mixed with Pear syrup, Gallic acid, Arginine (Arg), Lysine (Lys), Methionine (Met), or 8-Br-cGMP; plates containing Juvenile Hormone analog ZR-512, Brood Pheromone (BP), and Queen Mandibular Gland Pheromone (QMP) were placed inside the hives of another three treatments. Pollination efficacy was compared using the pollen load weight and quantity of foraging bees. The peak time of pear pollen gathering was 10:00–11:00 regardless of treatment. The pear pollen load weight per day was increased by all nine treatments. Pear pollen load weight per day was 49.11 g in the control. The QMP treatment yielded the heaviest pear pollen load weight per day (77.56 g), followed by the 8-Br-cGMP (64.45 g) and BP treatments (64.20 g). The percentages of pear pollen weight and quantity in the total pollen per day were both highest in the BP treatment (80.23%, 87.27%), followed by those in the QMP (79.32%, 86.74%) and Lys treatments (76.25%, 85.81%). In conclusion, BP was the most effective treatment for improving honeybee pollination behavior in the pear orchard, while other treatments, including Arg, Lys, 8-Br-cGMP, ZR-512, and QMP, could also be useful.
Volume 18, Issue 7 (11-2018)
Abstract
Inducers are important devices which are mounted upstream of the inlet to the main impeller of the centrifugal pump to achieve higher suction performance and rotate with the same speed as the impeller. Inducers improve the hydraulic performance and lifespan of the pump through increasing the inlet pressure, but the quantity of the improvement is dependent on the geometrical parameters of the inducer. Therefore, the optimization of these parameters is crucial. In the present study, the performance of an inducer is optimized by considering the inlet tip blade angle, the outlet tip blade angle and the ratio of the outlet hub radius to inlet hub radius as design variables and the head coefficient, the hydraulic efficiency and the required net positive suction head as objective functions. The inducer performance is simulated using 3-D computational fluid dynamics and compared with experimental data which shows the validity of the used method and assumptions. The artificial neural network is used to relate between design variables and objective functions. Then, the Pareto fronts are plotted using the modified non-dominated sorting genetic algorithm II and the proposed optimum points are presented using nearest point to the ideal point method. Using multi objective optimization, the head coefficient, the hydraulic efficiency and the net positive suction head are improved 14.3%, 0.3% and 30.2%, respectively. Recommended design points unveil important optimal design principles that would not have been obtained without the use of a multi objective optimization approach.
