The Resistance And Photosynthetic Response Of The Transgenic Tamarix Chinensis ThVHAc1 Gene Tobacco Under Salt And Alkali Stress

If photoinhibition in plants were occurred,the mechanism dependent of heat dissipation is one of the ways to protect the photosynthetic apparatus from harming.And heat dissipation is related to quenching of high energe state on the thylakoid membranes that relies on xanthophyll cycle.It were that one is heat dissipation to not depend on xanthophyll cycle,namely:the excess light energy in PS? reaction center reduced the pH between thylakoid membrane,and thylakoid membranes of high pH formed ApH,ApH made protein complexes in water-spiltting to inactivate,and retarded the PS ? donor side to transfer electron,P680+molecules can't restore,P680+ and the secondary electron acceptor Q_A electrical charge restructuring and reorganization of fluorescence,the heat dissipation slows down high-energy burden of the photosynthetic mechanism.The other depends on the heat dissipation of the cycle?qE?,which is produced by the photosynthetic electron transport across the membrane?pH controls.It is a kind of feedback regulation mechanism.When the chloroplasts absorb excess light energy,it will lead to produce higher ApH from the capsule body cavity and launch the qE.So when plants suffer adversity stress,photosynthetic mechanism will appear the phenomenon of excess light energy.And ApH of heat dissipation is very important.? pH and H+ from the membranes are closely related.Therefore,the paper from the tamarisk?Tamarix chinensis Lour.?ATPase cloned salt resistance in c subunit gene?GenBank:ACX50967.1?,which named ThVHAcl,using the method of mediated genetic transformation to the tobacco,obtains transgenic plants.Under the stress of salinity,through photosynthesis electron transfer,energy distribution and the state of electron acceptor,and the change of the variety of antioxidant enzyme in cells,revealed a Th VHAcl gene in plants defense mechanism in the role and function of the light damage,we provide reference for the salt resistance mechanism of plants.In ThVHAcl gene tobacco,which stressed salt?NaCl and Na₂CO₃?and wild tobacco?longjiang 911?as a control,we detect ThVHAcl gene tobacco growth index,fluorescence parameters,the change of antioxidant enzymes and osmotic regulation substances.The results show under mixed salt stress,Fv/Fm and ETR of the wild tobacco leaf significantly decrease at the same time,and the activity of PS? reaction center decline.Photosynthetic mechanism will accumulate excess excitation energy.PS ? reaction center lose the ability of charge separation,and it will cause the degradation of D1 protein inactivation and PS? reaction center.Mixing of salinity stress damage the PS ? reaction center.But Fv/Fm and ETR of the ThVHAc1 gene tobacco leaf to will reduce less than wild tobacco.Without D1 protein degradation and PS ?had significant effect on the reaction center,the activity of PS ? reaction center number more than wild tobacco.Under the mixed salt stress,CAT,APX,Pro,chlorophyll,SLW of Th VHAcl gene tobacco are higher than the other,and the relative electric conductivity less than the other.The photosynthetic ability is stronger than the other.A large number of experimental results show the Th VHAcl gene will improve the salt resistance of tobacco.