Study Of Calcium Regulation Effect On The Function Of Malus Baccata Borkh. Leaves Under Changing Temperature

This study using seedling of Malus baccata Borkh. as material, setting variable temperature treatment (5℃â†'20℃â†'10℃â†'0℃), combined with application of calcium compounds (1%CaCl2,2%CaCl2,5%CaCl2and1%CaAc2) and Ca2+chelator (EGTA), Ca2+channel blocker (LaCl3), plasma membrane Ca2+-ATPase inhibitor (SO) to study the process of substantial change temperature, the regulatory role of Ca2+on nitrogen metabolism, carbon metabolism, membrane lipid peroxidation, photosynthetic characteristics and leaf respiration metabolism of Malus baccata Borkh. seedling leaves, in order to explore the regulation role of expression of temperature adaptability of calcium on Malus baccata Borkh. seedlings withstand substantially constant temperature.The results as follows:1. In addition to the1%CaCl2treatments, other calcium salts treatment can be better protected the capture and utilization of light energy capacity of Malus baccata Borkh. seedling leaves, at the same time,2%CaCl2and1%CaAc2treatments significantly increased RuBPcase activity. Each treatment occurred photoinhibition in the cooling stage, but2%CaCl2and1%CaAc2treatments can alleviate photoinhibition extent at a lower temperature. At the same time, control and EGTA the function of the photosynthetic apparatus of Malus baccata Borkh. seedling leaves has been a marked decline. RC/CSo of calcium salts treatment compared with the control slightly lower, but ABS/RC and TRo/RC of different calcium salts treatment compared with the control was no significant difference, showed that calcium salts treatment improved energy capture efficiency of PSII. Different calcium inhibitors treatment dissipate more energy result in the transfer of energy is reduced, lower utilization of light energy.2. During the whole changing temperature, NR and GS activities of2%CaCl2and1%CaAc2treatments have been higher than the control, GOGAT activity was significantly higher than the control in the cooling phase, but NR, GS and the GOGAT activities of1%CaCl2and5%CaCl2treatments lower than the control in the cooling phase. NR, GS and the GOGAT activities of different calcium inhibitors treatment compared with the control has significant inhibitory effect.3. During the whole changing temperature, different calcium salts treatment can improve respiratory metabolism of Malus baccata Borkh. seedling leaves, maintain the leaves substrate metabolism pathway still TCA-led, mitochondrial electron transport chain leading to the CP, keeping Malus baccata Borkh. seedling leaves remained at relatively stablelevel.4. SOD, POD, CAT and APX activities of different calcium salts treatment with the control significantly improved,2%CaCl2and1%CaAc2deal with the level of increase is greater than1%CaCls and5%CaCla treatment, and calcium inhibitors treatment exacerbated protective enzyme activities reduced, EGTA treatment reduced amplitude.5. Under variable temperature conditions, MDA content of Malus baccata Borkh. seedling leaves significantly increased. But different calcium salts treatment can effectively reduce the MDA content; MDA content of EGTA treatment has been higher than the control, SO treatment higher than the control in the cooling phase, MDA of LaCl3treatment has been lower than the control.6. EP and CP activity of2%CaCl2and1%CaAc2treatments have been lower than the control, EP activity of different calcium inhibitors treatment have been higher than the control, CP activity of EGTA treatment has been higher than the control.