The Pattern of mitochondrial and chloroplast gene expression in Rice leaves in response to iron stress

Iron toxicity lead to oxidation of photosynthetic pigments, increasing of free radicals and as a result rice yield to be severely damaged. This study was performed to investigate the effect of iron toxicity on relative expression of alternative oxidase, external alternative NAD(P)H-ubiquinone oxidoreductase, internal alternative NAD(P)H-ubiquinone oxidoreductase, NADH dehydrogenase, NATPH-thioredoxin reductase and ferredoxin-thioredoxin reductase genes in two rice genotypes, IR64 (susceptible) and Pokkali (tolerant). Iron ion was applied at the levels of 0 (check), 100, 250, 400 and 500 mg.lit-1 under Yoshida hydroponic conditions. Results showed that the iron cosentration in leaves increased with increasing of stress levels. There was not a significant difference among IR64 treatments samples for leaves potassium cosentration. But it increased in Pokkali genotype relative to non stress samples .The expression levels of genes in Pokkali except NDH and IN-NDH in 250 and 400 mg li-1 and NTR in 500 mg li-1 samples were higher than IR64. In all, the difference of morphological traits and relative over expression of genes in Pokkali. In all, the difference of morphological traits and relative over expression of genes in Pokkali indicated that the gene could considerably effect on the tolerant level of pokkali by reducing ROS production under Fe-toxicity. Our results showed that high activity of the mitochondrial and genes, alone or together, could also be an important factor in iron tolerance in rice by detoxifying the harmful effects of the ROS.