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
R Khavarinejad, R. Shekaste-Band, F. Najafi, Z Gharari,
Volume 13, Issue 1 (5-2013)
Abstract
In order to understand some physiological mechanism of chilling and cold sensitivity in plants we investigate the effects of chilling and cold stress on chlorophyll and proline content, lipid peroxidation and variable chlorophyll fluorescence (Fv/Fm) of Arabidopsis (thaliana L.) The four weeks-old plants (WT, and four chilling sensitive mutants [chs2-2], [chs2-1], [chs1-2] and [chs1-1]) were subjected to two different low temperature treatments (control (23̊ C), chilling (13̊ C) and cold (4̊ C)), for one week. Fv/Fm and chlorophyll content changed significantly in all mutants except in WT by chilling stress (13̊ C), compared with control and 4̊ C treatments. Two out of four mutants, chs1-1 and chs1-2, had lowest chlorophyll content and Fv/Fm value among the tested genotypes. The proline content increased in all mutant genotypes, as well as in WT by chilling stress and 4̊ C, compared with control. MDA content of shoots changed dramatically in all mutant genotypes except in WT by chilling stress, compared with control and 4̊ C treatments. Our findings showed that two mutants, chs1-1 and chs1-2, have had highest chilling sensitivity among the tested genotypes and had the highest proline and MDA contents. It is possible that some damages in photosynthetic systems and/or in proline metabolism via mutation cause these plants more sensitive to chilling and cold stress
