Effects of Ca~(2+) on Photosynthesis and Related Physiological Indexes of Wheat Seedlings under Low Temperature Stress

First wheat seeds were treated with 40 mmol/L of CaCl 2 solution, and then their seedlings were put under low temperature stress. The result shows that the leaves photosynthetic rate, the chloroplast Hill reaction activity, the Rubisco activity, the contents of chlorophyll a, b and carotenoid in the treated group were much higher than that in control group′s, and the difference was significant. The results showed that the higher level of photosynthetic rate maintained by Ca 2+ under low temperature could be related with the higher activity of Rubisco and higher contents of chlorophyll a, b and carotenoid caused by Ca 2+ , but it was not related to chloroplast ATPase activity.