کبری یوسفی

The present study investigates the teaching method of solving the mathematical learning problem of high school students in Lordegan. In the present study, the statistical population is all high school students in Lordegan and sampling was done in a multi-stage cluster. Thus, the city of Lordegan was first divided geographically. One school from each geographical area and one school from each area among five districts, one school was randomly selected and 60 students from that school. Out of 60 people, 30 were randomly assigned to the experimental group in one class and 30 to the control group in another class. A standard learning questionnaire was used to collect data. In this study, analysis of covariance test was used to analyze the data. The results of the research showed that there is a significant effect between the teaching methods of solving the problem of mathematical learning of high school students in Lordegan.

The aim of this study was to investigate the ability of Lepidium draba L. seedlings to eliminate zinc and silver ions from the medium. The seeds of L. draba were cultured on MS solid medium for 15 days in the presence of different concentrations of both silver and zinc ions. The bioaccumulation of these ions in L. draba tissues were measured by atomic absorption. Furthermore, biochemical and morphological properties of the seedlings such as catalase and superoxide dismutase activities, total flavonoid content, germination percentage, root and stem lengths were analyzed. Results revealed that L. draba seedlings were able to absorb high level of zinc and silver ions and a direct relationship between the level of absorption and the amount of ions in media was seen. On the other hand, total flavonoid contents, catalase and superoxide dismutase activities were elevated by increasing concentrations of the ions in media. Silver ion increased the germination, while the seed germination did not show significant different in treatment with zinc ion in compared to the control. Upon the treatment seedlings with silver ion, the stem growth was significantly increased, while the root growth was decreased. Significant decrease in the stem and root growth were occurred upon seedlings treatment with high level concentrations of zinc ion. Based on the results, it seems that L. draba could be introduced an appropriate option for refining of the aforementioned metals from contaminated area.

In this study، effect of different concentrations of AgNO3 (for 4 hours treatment) and CuSO4 (for 16 hours treatment) elicitors were investigated on gene expression of FNS I and anti oxidant system in 21-day Cuminum cyminum seedlings. Semi-quantitative study of FNS I gene expression was shown a significant increase at 25 and 50 µM Ag concentrations rather than the control sample which decreased by the increase elicitor concentration up to 100 µM. On the other hand، by the increase elicitor concentrations، total flavonoid and anthocyanin contents and activity of some antioxidant enzyme as well as total protein content significantly increased. The gene expression were significantly elevated in treated seedlings by Cu elicitor at 4 and 8 µM treatments and its expression completely inhibited at 16 µM concentration. In this condition، total flavonoid and anthocyanin contents showed a similar trend and their contents were significantly reduced at 16 µM compared to the control sample. In contrast، the activity of antioxidant enzymes including catalase and superoxide dismutase، increased by the increase elicitor concentration، while total protein content drastically decreased. Based on the results، it deduced the increase FNS I gene expression and flavonoid and anthocyanin contents، were resulting in oxidative stress following absorption of these elicitors and activation of plant antioxidants system.

Lemon balm(Mellissa offisinalis L.) belongs to the Lamiaceae family with medicinal properties such as anti-bacterial, anti-depressants, anti-inflammatory, anti-cancer and anti-viral effects. The most pharmacological effects of this plant are related to its active ingredient, rosmarinic acid. In this research, the effects of different concentration of elicitors, yeast extract (0, 0.5, 1 and 2 mg/mL) and copper (0, 4, 8 and 16 μM) at different time intervals (4, 8 and 16 h) were investigated on rosmarinic acid and total flavonoid contents in 30-day-old seedlings of lemon balm greenhouse conditions. Results showed a significant effect of yeast extract on rosmarinic acid production, especially after 4 and 8 hours of treatment with this elicitor. The highest amount of this compound was observed in seedlings treated with 1 mg/mL of this elicitor. On the other hand, copper elicitor at all used concentrations and the duration time of treatment (except for 4 μM for 16 hours) significantly increased rosmarinic acid production, so that this elicitor at concentration of 8 µM for 8 hours treatment could induce rosmarinic acid level about 7-fold. It seems that the elevated level of this active ingredient under treatment with these elicitors is due to the induction of reactive oxygen radicals and jasmonic acid biosynthesis and subsequently expression of some genes involving in rosmaric acid biosynthesis.

Several studies have been investigated the effects of Yeast extract (YE) on morphological and biochemical properties of various plant species. In this research, isoflavone synthase (IFS) gene expression profile, flavonoid and anthocyanin contents and also activity of some antioxidant enzymes have been assessed in 9-day soybean (Glycine max) seedlings which were treated with various concentrations of YE for 8 and 16 hours. Soybean as an annual plant is a member of the Leguminoseae family. Its seeds are containing of isoflavonoid compound (such as genestin and dedzein) which produce through IFS catalyzes from flavonone precursor. Results showed flavonoid and anthocyanin contents, IFS gene expression and also protein content significantly increased in elicited seedlings in compared to that of the control, but more significantly at 16- hour treatment. On the other hand, activity of antioxidant enzymes including superoxid dismutase, catalase and peroxidase was also elevated in treated seedlings rather than of the control that was more remarkable at 8-hour treatment. Based on the results, it can be concluded that treated soybean seedlings with YE lead to induce an oxidative stress. In this condition, while at 8-hour elicitation time the enzymatic antioxidant systems is more active, higher activity of the non-enzymatic antioxidant system (phenyl propanoid pathway) was seen for 16 hours treatment. Therefore, it seems that YE-treated for 16 hours is optimal for inducing of gene expression and also biosynthesis of active ingredient in this plant.