Chin J Plant Ecol ›› 2005, Vol. 29 ›› Issue (6): 985-991.DOI: 10.17521/cjpe.2005.0131

• Research Articles • Previous Articles     Next Articles

EFFECTS OF NACL STRESS ON ACTIVE OXYGEN METABOLISM AND MEMBRANE STABILITY IN PISTACIA VERA SEEDLINGS

YUAN Lin1, KARIM Ali2, ZHANG Li-Quan1,*()   

  1. 1 State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
    2 Institute of Horticulture, Xinjiang Agricultural University, árümqi 830052, China
  • Received:2005-01-03 Accepted:2005-05-27 Online:2005-01-03 Published:2005-09-30
  • Contact: ZHANG Li-Quan

Abstract:

Pistachio (Pistacia vera) is one of the most important dried fruit trees in the world and is mainly cultivated in Xinjiang, China. However, soil salinization is one of the main limiting factors for its promising potential of development. In this experiment, the effects of NaCl stress on physiological and biochemical characteristics were investigated in seedlings of two cultivars of Pistacia vera, `Changguo' and `Kerman'. Seedlings were grown in pots and treated with four NaCl concentrations: 50, 150, 250 and 500 mmol·L-1. The membrane permeability, malondialdehyde content (MDA), superoxide dismutase (SOD) activity, catalase (CAT) activity and peroxidase (POD) activity in the leaves of these two cultivars were measured and compared after 5, 10 and 20 days of NaCl treatments.
The experimental results showed that the membrane permeability and MDA content in both cultivars increased considerably with the increasing NaCl stress, which aggravated the degree of membrane lipid peroxidation and injured the membrane stability. The membrane permeability and MDA content in the `Changguo' cultivar increased more quickly than the `Kerman' cultivar and thus experienced greater damage at higher NaCl concentrations. The activities of SOD, CAT and POD had similar trends for both cultivars, first increasing with NaCl concentrations up to 250 mmol·L-1 and then decreasing at the highest NaCl stress of 500 mmol·L-1. The coordinated changes of activities among the antioxidant enzymes of SOD, POD and CAT could scavenge active oxygen and maintain a balance of active oxygen accumulation in cells to protect membrane structure. The results also showed that the damage by NaCl stress to the membrane structure and function for both cultivars were mitigated considerably 20 days after the treatments were initiated. There were significant correlations among the membrane permeability, MDA content and the activity of SOD in both cultivars, which implied that the membrane permeability in the plant cells had a close relation with MDA content and oxygen free radical content, as well as the activity of antioxidant enzymes. Together, these results indicated that the `Kerman' cultivar has higher antioxidant levels and greater salt-tolerance than the `Changguo' cultivar of Pistachio.

Key words: NaCl stress, Pistacia vera, Membrane permeability, MDA, SOD, CAT, POD