Plants have developed various mechanisms to protect themselves against oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid. There is thus a need for a rapid, sensitive method for the analysis of the reduced and oxidised forms of ascorbic acid in crop plants. In this paper a simple, economic, selective, precise and stable HPLC method is presented for the detection of ascorbate in plant tissue. The sensitivity, the short retention time and the simple isocratic elution mean that the method is suitable for the routine quantification of ascorbate in a high daily sample number. The method has been found to be better than previously reported methods, because of the use of an economical, readily available mobile phase, UV detection and the lack of complicated extraction procedures. The method has been tested on Arabidopsis plants with different ascorbate levels and on wheat plants during Cd stress.
Authors:Tibor Janda, Eszter Kósa, János Pintér, Gabriella Szalai, Csaba Marton, and Emil Páldi
Six maize hybrids and their parental inbred lines, grown under controlled conditions, were tested for chilling tolerance using the chlorophyll fluorescence induction technique. The genotypes were ranked based on the decrease in the F
parameter after chilling stress at 5°C. The activities of enzymes playing a role in stress defence mechanisms (catalase, glutathione reductase, ascorbate peroxidase, guaiacol peroxidase and glutathione-S-transferase) were determined in control plants and after 1 day of cold treatment. The results suggest that although there are differences between the genotypes in the activities of almost all the antioxidant enzymes, these differences do not reflect the differences in the chilling tolerance.