جستجوی مقالات مرتبط با کلیدواژه « physalis » در نشریات گروه « زیست شناسی »

Drought stress is the most unfavorable environmental factor that severely reduces plant growth and production. Jasmonates, as the plant growth regulators, and effective in physiological processes, increase plant tolerance to stressful conditions. Physalis is a medicinal plant belonging to Solanaceae family. In order to investigate the effect of methyl jasmonate (MeJA) pretreatment and drought stress on the physiological and biochemical responses of Physalis. A factorial experiment was conducted with the combination of two factors, moisture levels [100% (control), 50%, and 30% of field capacity (FC)] and MeJA levels (0, 50, and 100 µM). Plants were exposed to different levels of moisture for two months, 24h after foliar application of MeJA. The results showed that pretreatmment of plants with MeJA increased leaf area, RWC, total plant dry weight, total chlorophyll, and carotenoids by 36.48, 31.07, 178.53, 37.11, and 49.73%, respectively during drought stress. In this research, application of MeJA, especially concentration of 100 µM, by increasing the contents of soluble sugars (12.13 and 16.69%), proline (22.84 and 45.86%), flavonoids (14.01 and 21.69%), protein (16.53 and 20.98%) and activity of SOD enzyme (22.09 and 13.96%) and decreasing the activities of POD (12.82 and 39.06%), APX (20.85 and 17.33%) and PPO (14.83 and 18.68%) enzymes in the shoot and root, moderated the negative effects of drought stress especially at 30% FC level. Also, MeJA induced changes in the accumulation and distribution of mineral nutrients in stressed plants. The results of this research showed that the foliar application of MeJA by improving the growth and photosynthetic properties, antioxidant system and nutritional status could be an appropriate solution to increase the tolerance of Physalis plant to drought.

 This study aimed to investigate the effect of microgravity and light spectral composition on the levels of antioxidant enzyme activity, minerals, and  some photosynthetic pigments in Physalis alkekengi.

This study was performed in vitro. Seedlings were exposed to the microgravity treatments under two different light conditions, including white (C) and red+blue (R+B).

 The microgravity treatments were more capable of rapidly influencing growth performance than the light spectrum quality. Red+blue light increased the amount of chlorophyll a and b. Antioxidant enzymes under microgravity stress showed an increase, while changing the quality of the light spectrum did not make a significant difference. An increase in malondialdehyde (MDA) was observed in the microgravity treatment compared to the light spectrum. The amount of Cu+2 and Zn+2 were increased by the R+B+microgravity treatment. However, Mn+2 was increased in the microgravity treatment. The highest uptake of Fe+2 and Ca+2 was recorded under microgravity conditions. R+B+Microgravity treatment increased K+ content compared to white control. The microgravity treatment increased Mg+2 in the root cell.

 In general, microgravity and light spectrum can increase biomass. Microgravity has little effect on photosynthetic pigments, but the R+B light spectrum increased the pigments. Microgravity increased the activity of antioxidant enzymes and the content of MDA. The concentration of some elements in roots and leaves can be modified by the light and microgravity conditions.

DNA methylation detection by a novel fluorimetric nanobiosensor for early cancer diagnosis Quantum dots as a fluorescent probe are applied for cell biology, DNA transformation, biomedical imaging and cancer therapy. Biological based synthesis of nanoparticles would be more efficient and environment friendly rather than chemical approaches. In the present study, quantum dots have been synthesized through leaf methanolic extracts. The obtained results by UV-vis spectroscopy, TEM, FT-IR and fluorescence spectroscopy showed the presence of synthesized CdS quantum dots. Yellow and orange colors of obtained solution was also indicated the successful synthesis of CdS quantum dots. The maximum UV-Vis spectrum absorption of quantum dots was observed at 410 nm. Results of fluorescence analysis also showed that emission bands were at 475, 490 and 675 respectively which indicated the synthesis of different CdS quantum dots in different pH values. Obtained nanoparticle were spherical and at the range between 2-10 nm according to TEM analysis. FT-IR analysis also showed that the proteins, leucine and lysine amino acids, phenols and other functional groups present in physalis extracts would be determining factors for reducing CdS ions and converting them to quantum dots.