Effect Of La On Pisum Sativum L. And Zea Mays L. Seedlings Under Heavy Mental Stress

This thesis included three parts. In this paper, the seedlings of Pisum sativum L seedlings were cultivated for in solution containing different concentration of Hg, Cd and La; The Zea mays L. seedlings were cultivated in solution containing different concentration of Cd and La. The results show that La alleviates the reduction of chlorophyll and soluble protein content, increases the activity of whole electron transport chain, PSII and Mg2+-ATPase in chloroplast, protects the absorption spectrum and fluorescence emission spectrum at room temperature from being affected by Hg and Cd stress, and proteacts the activity of PEPC under the Cd stress, thereby lightens the hurt on photosynthesis La is more effective against 10mg/L Hg treatment than 50mg/L one, or 10mg/L Cd than 30mg/L Cd. 0.010mg/L La is most optimum when added to solution and0.50mg/L when sprayed. However, La which under the concentration exceeds certain limit aggravates the stress of high Hg concentration.In the second part, the results show that La also increases the total antioxicatability (including SOD, CAT, GSH, and ASA), deletes O2- and MDA, reduces the relative membrane permeability. Besides, it lessens the absorbability and accumulation of Hg and Cd. Most of La is out of the membrane.In the third part, we detected the iron content and activity of TM- and TP-H+-ATPase. The results show that La keeps iron balance and protects two kind of H+-ATPase and H+-PPase against the Cd stress. TP-H+-ATPase is more sensitive to La than TP-H+-ATPase. does.