Studies On Characteristics Of Reactive-Oxygen-Scavenging Enzymes,Osmotic Adjustment Substances & Ion Absorption,Distribution Of Three Species Oleaster Under NaCI Stress

Elaeagnus L. is one kind of important economical tree in Xinjiang Uygur Autonomous Region. It has great ability to adapt many extreme environmental conditions,such as drought,cold,salt & alkali and sand burying,it is a very good candidate for controlling and remediation of saline alkaline and deserted soil . In addition, it has great significance to the progress of the society, the development of the economy and the maintenance of ecosystem healthy in northern west region. One-year-olds seedling of E. oxycarpa Schlecht.,E. mooceroftii Wall.ex Schlecht and E angustifolia var orientalis Kuntze. were subjected in this experiment as materials .The control and five NaCI treatment were designed ,NaCI concentration is 50,100,200,300 and 350mmol/L respectively, NaCI was controlled and treated for 10,20,30 days by EC of NaCI method in potted mulberry under the rainproof awning. This experiment studied the characteristics of Reactive-Oxygen-Scavenging Enzymes,Osmotic Adjustment Substances &Ion absorption,distribution in three species Oleaster seedlings under NaCl stress. The results are summarized below:1) The membrane permeability and contents of MDA in leaves of three species Oleaster increased with the increase of NaCl concentration and prolonging of time. Among them, the range of increased contents of MDA in leaves of E. oxycarpa Schlecht. was smaller than the E. mooceroftii Wall.ex Schlecht and E angustifolia var orientalis Kuntze at whole treating processes. Content of H₂O₂ in leaves of E. oxycarpa Schlecht. and E. mooceroftii Wall.ex Schlecht increased rate a certain degree and then decreased with the increase of NaCl concentration and prolonging of time. Contents of H₂O₂ in leaves of E angustifolia var orientalis Kuntze concerd increased trend with the progressive increase in salt level of the growth medium at whole treatment.2) After three species oleaster were treated NaCI stress ,the change of antioxidant enzyme activities seemed like be in different characteristic. When they were treated NaCI stress for 10,20days, SOD,CAT,POD and APX activities in leaves of three species oleaster increased a certain degree and then decreased with the increase of NaCl concentration.Howevre, treatment concentration of presented maximum peak and the change degree of these antioxidant enzyme activities was varied as different spiecies. At Stress for 30d, antioxidant enzyme activities represent different characteristic, SOD and CAT activity in leaves of E. oxycarpa Schlecht.and E. mooceroftii Wall.ex Schlecht. maintained markedly higher activity. and that, under NaCI concentration above 100mM stress, POD activity of three species oleaster all decreased than stress prophase.,but POD activity at NaCI treatment ia also higher than POD activity of control.3) Three species oleaster seedling under NaCI stress for 10,20,30d,the Proline and Soluble Sugar content in leaves of them increased with the increase of NaCl concentration; Under same salt stress condition, the Starch content change trend in contradiction to soluble sugar. The content of soluble protein in leaves of them have change under NaCI stress. Howevre, the range of variation and tendency have distinction on the basis of different Oleaster spiecies. 4) Na⁺ concentration in root,steam and leaves of three species oleaster seedling were increased with NaCI stress increasing. The increasing range of Na⁺ concentration in leaves of E. oxycarpa Schlecht.is highest in among others. At the same NaCI concentration, Na⁺ and K⁺ concentration in leaves and stem of three species oleaster seedling were higher than that in root, so stem and leaf was the main site of Na⁺and K⁺ accumulation; K⁺ concentration in leaves changed irregularly, the levels of change K⁺ concentration in root and stem was comparatively smooth out. Ca²⁺ concentration in different tissue of three species oleaster in turn by high to low is root>stem>leaf, Ca²⁺ concentration of E angustifolia var orientalis Kuntze came under the influence of NaCI stress in favor of others. The NaCI stress have no significantly influence Mg2+ concentration in different tissue of three species oleaster;Under NaCI stress K⁺ / Na⁺ in different tissue was decreased gradually,the ratio in turn by high to low is leaf>stem>root.however, the change of Ca²⁺/ Na⁺ is inconsistent.With NaCl concentration increase, K-Na transport selectivity ratio (SK,Na) declined with varing degrees compared to control, but there is no significant difference in comparement of each NaCI treatment.5) Through correlation analysis about physiological indexes, the results showed: MP increase was extremely significantly positive correlation with the concent of MDA, the membrane lipid peroxidation was the main factor to the damage of the cell structure and function. there were positive or negative correlation between SOD,CAT,POD,APX and MP,MDA contents. This indicated that each Reactive-Oxygen-Scavenging Enzymes play different roll to respite salt injury at different NaCI treatment times. Under the salt stress, the contents of proline were increased significantly. The correlation analysis indicated that there were extremely significant positive relations between proline and the MP, MDA contents. This positive relation showed that the increasing of proline has no direct protection effect to cell membrane, but proline had closed relation to protective enzyme. There were extremely significant positive relations between Na⁺concentration in leaves and the MP, MDA contents of three species oleaster.6) Three species Oleaster have quite strong adabtation ability to salinity envormental and resistance to oxidation,osmoregulation ability. The growth was restrained under NaCI stress, but they could still survival under 350 mmol/L NaCI treatments for 30days. Even all species are not representing refuse salt characteristic during under salt stress. Wherefrom inference that Oleaster likely to through Na⁺ compartmentation at intra-cellular that Na⁺ be storaged in vacuole. On the one hand respited osmotic stress, on the other hand relieved Na⁺ harm to cytoplasma membrane. Thereby, Oleaster appears to be of definite salinity tolerance ability.