s.b. mousavi

Under water stress conditions, growth-promoting rhizobacteria could alter root characteristics, leading to increased plants yield. A controlled experiment with two barley cultivars, Dasht, and Kavir, was carried out with four inoculations of Bacillus simplex strains (31-2, 42-3, 51-4, and control), in two irrigation levels of 80 and 50% of field capacity. The results showed that inoculation with the mentioned bacteria increased the biological yield of barley by 28% under water stress condition compared to the control treatment. The effect of bacteria was cultivar dependent. B. simplex 31-2 had the most significant effect on the biological yield of Kavir cultivar, and B. simplex 42-3 on the Dasht cultivar. Linear relationships between root characteristics and barley's biological yield were observed. The highest coefficients of determination (R2) were obtained with fresh root weight (84%), root volume (83%), and root surface (81%). Considering the relationship between root traits and the biological yield of barley and the role of B. simplex 31-2 in a 121% increase in root area under water stress, it seems that this trait is the essential mediator of yield. Due to the insignificance effect of B. simplex 3-32 on the root characteristics, against the increase of shoot performance by this bacterium, its mode of action may be due to inducing improvement on other physiological pathways. Overall Bacillus bacteria are effective in mitigating the negative effect of water stress on barley and these bacteria can be considered effective candidates for the production of biofertilizers.

The presence of cadmium in the soil is a major threat to plant growth and productivity. Plants often accumulate cadmium in their edible part, reducing the yield and quality of the product. In order to evaluate the effect of different concentrations of potassium (100, 200 and 300 mg L-1) under different levels of cadmium (0, 2 and 4 mg L-1) stress in tomatoes and potassium efficiency in reducing stress effects, a factorial experiment based on a completely randomized design was carried out with 3 replications. The results showed that with raising the cadmium concentration, malondialdehyde content, hydrogen peroxide content and guaiacol peroxidase activity were increased. The interaction effect of cadmium and potassium on the Fe concentration in the fruits and Zn concentrations in the leaves and fruits of tomatoes was not significant; however, the use of each of them alone had a significant effect; so, potassium consumption increased the concentrations of Fe, Zn and K in the fruits and decreased the malondialdehyde and hydrogen peroxide. The results of greenhouse experiments showed that the use of potassium nitrate fertilizer improved the efficiency of the plant phytoremediation in reducing the cadmium stress, although it is necessary to continue research in the field.

Normal healthy pulpal tissues were obtained from 19 impacted molars and symptomatic samples were obtained from 18 carious molars and premolars clinically diagnosed in all vital pulpal tissues. Student''s t-test revealed significant differences in IL-2 concentrations, comparing symptomatic pulpal tissues with normal healthy samples (657, p)