Silicon Ziziphus Jujuba Salt Stress Relief Effect And Its Mechanism

The soil of salt and alkali is one of the key stress factors inhibiting survival rate, growth,fruit yield and quality of Ziziphus jujuba Mill. The research on salt tolerance and controltechnology of jujube is very little in world wide. The availability of silicon in soils for plants isusually low though it is the second abundant element in soils. The research on physiologicalfunction of silicon for plants has been recently focused on.The main object of this study was focused on the relation between silicon and salttolerance of Z.jujuba cv.jinsixiaozao and their mechanism. The test material was 1-years oldgrafting seedlings. X-ray electron probe microanalysis, ultra-structure observation and analysis,High Performance Liquid Chromatography(HPLC)and other scientific methods were used torelease the secretary. The research involved the ultra-structure of cell, the distribution of ionmicro field, the forms and content of Polyamines, the absorption and allocation of mineralelement, the activity of various types of enzyme, etc. The main results of the research werepresented as follows.Firstly, with the increase of soil salt content, the growth of stem and root and the totalbiomass of Z.jujuba cv.jinsixiaozao were all decreased. If the content of salt is little than 0.3%,with the addition of the fertilizer of silicon, the indications above were enhanced; if the contentof salt is 0.4%, with the fertilizer of silicon, the indications above were enhanced appreciably.The effect of the indications was best when the silicon content was 0.5‰.Secondly, when the content ration of salt is 0.2%, the cell of Z.jujuba cv.jinsixiaozao didn'tappear phenomena of the plasmolysis. Nevertheless, with the salt stress of the salt contentration is 0.3% and 0.4%,the leaf ultra-structure was changed remarkably. The double membraneof chloroplast was broken off. The stroma lamella structure was completely destroyed. Thestarch grains were decreased, with silicon fertilizer, it alleviated the damage of salt stress on thecell ultra-structure of Z.jujuba cv.jinsixiaozao, kept the integrity of chloroplast lamella structure,decreased the dilapidation of membrane system, delayed the senescence and disorganization ofchloroplast. This result was shown that, under salt stress, with silicon fertilizer, thephotosynthesis function was protected and the capability of osmotic adjustment was enhanced.Thirdly, with the increasing of the content ration of NaCl, the content ration of the ion ofNa and Cl and the ratio between the ion Na and Cl in the stem, root and leaf of Z.jujubacv.jinsixiaozao was went up remarkably, but the content ration of the ion of K was fall. Withsilicon fertilizer, the content ration of the ion of Na and Cl and the ratio between the ion Na andCl in the stem, root and leaf of Z.jujuba cv.jinsixiaozao was fall, but the ion of K was went up.This result was shown that, under salt stress, silicon kept the ion balance in the plants and theion homeostasis in photosynthetic cells. Fourthly, with silicon fertilizer, the situation of micro-domain distribution of Z.jujubacv.jinsixiaozao under salt stress had been improved. The X-ray peak value of the content of theion of Na and the ion of Cl in the epidermis,cortex and stele cell of root descended significantly,but this of the ion of K ascended. It caused the uniform distribution of the ion of Na and Cl inthe transect of root, so the damage of salt on Z.jujuba cv.jinsixiaozao was consequentlyalleviated.Fifthly, salt stress had the effects of silicon on changes of glutathione peroxidase (GSH-Px)and superoxide dismatase (SOD) and peroxidase (POD) activity of Zizyphus jujube cv.Jinsi-xiaozao. SOD and GSH-Px activity increased with increasing salinity under salinityconditions, POD activity increased under 0.25% NaCl and decreased under 0.4% NaCl. Withsilicon fertilizer, SOD, POD and GSH-Px activity was maintenance. Accordingly, it alleviatedthe damage of membrane of active oxygen.Sixthly, under salt stress, the content of f-put was fall, but the content of f-spd, f-spm andPISCC-PAs were gone up. With silicon fertilizer, the content of f-put in the leaf was risen andthe transformation between the content of f-put and the content of f-spd, f-spm PSCC-Pas andPISCC-PAs were promoted. It increased the capability of the cell osmotic adjustment andrelieved the damage of f-put. With the combination of Polyamines and Protein molecular incovalence type, it could adjust the biologic function of protein and could stabilitate the spacestructure of protein, delay the decomposition reactivity of protein under salt stress.