Effects of Elevated Atmospheric CO2 and O3 on Hill Activity and Ca2+/Mg2+-ATPase Activity of Pinus tabulaeformis Carr.

The main photo-physiological characteristics of Pinus tabulaeformis Carr. were analyzed in open-top chambers under elevated carbon dioxide and ozone concentrations. The results indicated that the leaves net photosynthetic rates ( p < 0.05), Hill activity, Ca²⁺/Mg²⁺-ATPase activity, soluble sugar and starch contents all increased under elevated carbon dioxide concentration in whole growing season. While under elevated ozone concentration, the leaves net photosynthetic rates, Hill activity, Ca²⁺/Mg²⁺-ATPase activity, soluble sugar and starch contents all decreased. Under elevated carbon dioxide and ozone concentration, the leaves net photosynthetic rates, Hill activity, soluble sugar and starch contents all increased, but Ca²⁺-ATPase activity increased during the earlier growing season, decreased in later growing season, while Mg²⁺-ATPase activity responded contrarily. [ABSTRACT FROM AUTHOR]