Changes Of Ca²⁺ And Ca²⁺-ATPase Activities In Cells Of Populus Euphratica And P.euramericana Under Salt And Drought Stress

Ca2+plays roles in sustaining the balance level of the ion and the water in plant cells, and it's a component part of cell's protective system as well as the most important second messenger in plant cells; Ca2+-ATPase plays significant roles in keeping the concentration of Ca2+balanceable in cytoplasm, improving plant cell's performance of stress tolerance and keeping cells alive and active under various stress in a certain degree. The stress induce some kind of signal which will be transferrsd into cells, then some certain actions such as Ca2+and Ca2+-ATPase will be taken place,which will response to the corresponding external circumstance. That process is various according to different organs of a plant as well as different organelles of a cell. So studying this mechanism will assure our scientific practice.Both Populus euphratica and P.euramericana are ligneous plant, whereas they have adverse tolerances to stress. According to this we have chosen them as materials,aiming to analyze and compare them under the same treat—drought and salinity. We take advantages of X-ray technology and electron microscop-cytochemical method to analyze the energy spectrum and the location of sedimentation in both quality and quantity aspects,which is extremely helpful to study the effect of Ca2+and Ca2+-ATPase in plants.The experimental has revealed that Ca2+level of both polar decreased with the strengthening of stress in vacuole,yet is adverse in cytoplasm.The activity of Ca2+-ATPase in plasma membrane and tonoplast of the two polar are different under drought and saline stress.It's always more activated in Populus euphratica,although it has decreased a lot after a temporary increase in the first 16 days. While to P.euramericana,it lasted decreaseing with the intensity of stress.