Responses to chilling stress in French bean seedlings: Antioxidant compounds

French bean (Phaseolus vulgaris L. cv. Contender) plants at five developmental stages (4, 8, 12, 16 and 20 d after sowing) were exposed to one of three treatments: 1 - 25 degrees C (control), 2 - exposure to chilling at 10 degrees C only for 2 d prior to sampling, and 3 - long-term exposure to chilling at 10 degrees C. Short- and long-term chilling decreased plant growth. Higher concentrations of ascorbate and glutathione were found in the chilling-treated plants throughout the different period of growth in comparison with those in the control plants. The activities of superoxide dismutase, ascorbate peroxidase, and glutathione reductase increased in the chilling-treated seedlings while activities of catalase and peroxidase and of beta-carotene content decreased in young chilling-treated plants and slightly increased in older ones.