Elevated atmospheric CO₂ concentration enhances salinity tolerance in Aster tripolium L

• Published in: Planta 2010-02, Vol.231 (3), p.583-594
• Main Authors: Geissler, Nicole, Hussin, Sayed, Koyro, Hans-Werner
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases - metabolism; Agriculture; Antioxidants - metabolism; Aster Plant - drug effects; Aster Plant - enzymology; Aster Plant - metabolism; Biological and medical sciences; Biomedical and Life Sciences; Carbon dioxide; Carbon Dioxide - pharmacology; Cash crops; Detoxification; Ecology; Enzymatic activity; Forestry; Fundamental and applied biological sciences. Psychology; Hydroponics; Ion transport; Life Sciences; Original Article; Oxidative Stress; Plant Proteins - chemistry; Plant Proteins - metabolism; Plant Sciences; Proteome; Salinity tolerance; Salt-Tolerance - drug effects; Seawater; Sodium chloride; Sodium Chloride - metabolism
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-009-1064-6

Our study aimed at investigating the influence of elevated atmospheric CO₂ concentration on the salinity tolerance of the cash crop halophyte Aster tripolium L., thereby focussing on protein expression and enzyme activities. The plants were grown in hydroponics using a nutrient solution with or without addition of NaCl (75% seawater salinity), under ambient (380 ppm) and elevated (520 ppm) CO₂. Under ambient CO₂ concentration enhanced expressions and activities of the antioxidant enzymes superoxide dismutase, ascorbate peroxidase, and glutathione-S-transferase in the salt-treatments were recorded as a reaction to oxidative stress. Elevated CO₂ led to significantly higher enzyme expressions and activities in the salt-treatments, so that reactive oxygen species could be detoxified more effectively. Furthermore, the expression of a protective heat shock protein (class 20) increased under salinity and was even further enhanced under elevated CO₂ concentration. Additional energy had to be provided for the mechanisms mentioned above, which was indicated by the increased expression of a β ATPase subunit and higher v-, p- and f-ATPase activities under salinity. The higher ATPase expression and activities also enable a more efficient ion transport and compartmentation for the maintenance of ion homeostasis. We conclude that elevated CO₂ concentration is able to improve the survival of A. tripolium under salinity because more energy is provided for the synthesis and enhanced activity of enzymes and proteins which enable a more efficient ROS detoxification and ion compartmentation/transport.