Latifeh Pourakbar, ,
Volume 13, Issue 1 (5-2013)
Abstract
Copper and nickel are an essential micronutrient for plants, playing an important role in maintaining plants' natural metabolism and growth, but in excess both heavy metal are also a proven inhibitor of various physiological functions. In this study maize (Zea mays L.) plants grown in hydroponic culture were treated with CuSO4 (0, and 100 &mum),NiSO4 (0,100 and 200&mum)and interaction of CuSO4 (100 &mum)and NiSO4 (100 and 200 &mum). After 1 mounth of treatment, growth parameters and some biochemical changes were studied in roots and shoots of plants. The results showed that with increasing Cu and Ni concentration, pigment contents (chlorophyll a, b and total carotenoids), root and shoot length and dry weight were decreased, while k+ leakage, malondealdyde as indicator lipid of peroxidation and some antioxidant enzyme activity were increased. Also result showed that interaction of Cu and Ni has been cooperation effects on together and intensify each other's work
Latifeh Pourakbar, Latifeh Pourakbar,
Volume 15, Issue 2 (2-2015)
Abstract
Effects of decreased ozone and increased UV radiation have been studied by many researchers. The aim of this study was to investigate the effects of UV-B radiation on Melissa officinalis L. and to study the impact of salicylic acid and magnetic fields in reducing the harmful effects of radiation on plants. The Melissa officinalis L. plants were treated with 28_+2 Celsius temperature for about 60 days. The light intensity was 150 µ E mˉ² Sˉ¹ and the lightness-darkness condition was8-16 hours. UV treatment was applied after the six-leaf stage and UV-B radiation was applied for a period of 15 days, the time for each application was 20 minutes. Salicylic acid was sprayed on the plants after the six-leaf stage with a concentration of 1 mmol. Magnetic field treatment was applied for an hour with intensities of 0, 40 and 85 mT. The results indicated that the UV-B radiation led to reduction in dry and fresh weight, root elongation and shoots. The radiations also reduced the photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoid) and sugar rate and soluble proteins amount. The phenylalanine ammonia-lyase compounds rate and UV-absorbing compounds were increased under the effect of UV-B radiation. The results showed that treatment with salicylic acid and magnetic fields caused a reduced damage to the plant which had been created due to UV-B radiation and were able compensate for changed factors that had been changed because of UV radiation.
