Spatial And Temporal Variations Of Calcium, Calmodulin, Calcium Pump Of Banana Seedlings Under Salt Tolerance

Banana(Musa spp.) is one of the most important tropical and subtropical fruit, but in the production of salinization severely limited the development of the industry. Calcium as an important second messenger,participate in many plants to adversity signal transduction. we prove that calcium physiological mechanism in banana adjust salt stressb earlier stage, but Ca2+ distribution,changes in CaM Content, Ca2+-ATPase activity and the characteristics expression of CaM gene and Ca2+-ATPase gene has not been reported during calcium signaling startup. The experiments were conducted artificial simulated salt stress environment at 60 mmol·L-1NaCl, which Banana seedlings of Ca2+ and subcellular localization under NaCl stress 0, 4, 8, 12, 24 and 48 h at different times, by adding exogenous Ca2+ and extracellular Ca2+ chelator EGTA treatment,measured CaM content on roots and leaves , Ca2+ -ATPase activity, the relative expression amount of CaM gene and Ca2+ -ATPase gene to a salt of calcium signaling system regulating banana Stress tolerant mechanisms to provide a theoretical basis.The major study as fellow:1. Ca2+precipitated calcium pyrophosphate antimony particles appear in the identification of a large number of intracellular vacuoles, and showed a uniform distribution, chloroplast Ca2+ less distribution under normal growth conditions. Ca2+ in banana seedlings decreased vacuole,causing an increase in extracellular Ca2+. There are a lot of coke particles of antimony precipitated calcium cell wall under NaCl stress.2. The CaM content of banana seedlings’ leaf and root was increased significantly under the salt stress.The content of CaM was significantly increased by add calcium under salt stress,treatment with reduce calcium was significantly reduced,which the plant wil increase the concentration of calcium to combine with calmodulin to relieve the discomfort of stress does adapt under salt stress.3. Banana seedlings roots and leaves of the plasma membrane, tonoplast membrane,endoplasmic reticulum Ca2+-ATPase activity was significantly higher than that of CK, salt stress, and reduce calcium treatment under salt stress add calcium.Calcium deficiency in the process of salt stress, roots and leaves of banana seedlings of plasma membrane,vacuole membrane, endoplasmic reticulum of retinal Ca2+-ATPase activity were significantly lower than control treatments.In salt stress 4 h, adding calcium treatment the membrane calcium pump activity were significantly increased, calcium deficiency treatment was significantly reduced.Add calcium treatment improved the Ca2+-ATPase activity,which can guarantee under stress can make the Ca2+ in a relatively steady state,raise the adaptability of the banana in salt stress.The plasma membrane and tonoplast membrane of Ca2+-ATPase was the key to regulation intracellular Ca2+of banana. Which can maintain the steady-state level of low concentration Ca2+ in the cell By improving the plasma membrane and tonoplast membrane of Ca2+-ATPase activity.4. The root and leave of the seedlings of banana’s CaM gene and Ca2+-ATPase gene have express under the condition of normal hydroponic.The seedlings of Brazil banana’s CaM gene did not change significantly under salt stress but the root of Fenjiao has change significantly,which may be related to Fenjiao salt resistance higher than Brazil banana.By over time of the salt stress Brazil banana and Fenjiao seedlings root relative expression of Ca2+ -ATPase gene are present first after rising downward trend.