Abstract: In order to understand the response mechanisms of Pogonatherum crinitum growing in contaminated mining areas, a pot culture experiment was carried out to study the physiological indexes of P. crinitum under varying Pb stress concentrations. Low Pb concentration (1000 mg·kg^-1) had promotional effects on POD activity, soluble protein content in leaves and ASAFR activity, and on soluble sugar content and proline content in roots, allowing P. crinitum plants to maintain their overall antioxidant capacity at a high level and promoting plant height, leaf length and biomass. Increasing Pb concentrations (2000, 3000 mg·kg^-1) inhibited shoot height, leaf length, leaf area and biomass, but increased the MDA content of plants. P. crinitum’s adaptability to high Pb concentration treatments was evident as increasing POD and CAT activities in leaves and roots to enhance antioxidant activity, as increasing soluble protein and soluble sugar content to maintain the normal operation of cells, and as the promotion of root development and root∶shoot to keep T-AOC at a high level. These findings indicate that P. crinitum can adapt to Pb stress by adjusting its antioxidant system and enhancing its osmotic adjustment substance contents, suggesting that the plant has application potential for the remediation of Pb polluted soil.

Key words: Pogonatherum crinitum, Pb stress, antioxidant system, proline