Effects Of Salt Treatment On Succulence And Aquaporins Of Suaeda Salsa Seedings

In order to endure salinity, salt-dilution halophyte, the Suaeda salsa took the most important measures of succulence of some organs. Salt treatment had effects on growth, succulence and some physiological parameters. In present study, Suaeda salsa seedlings were treated with different salts and isoosmotic PEG to examine the succulence and some physiological parameters. The hydraulic conductance (Lo) of the roots, the water permeability of protoplasts and Western blot analysis of aquaporins in plasma membrane and tonoplast under NaCl were determined. The main results were shown as follows:1. Effect of salt treament on seeding succulence1.1 Effect of NaCl treament on seeding succulenceThe succulence was markedly stimulated by low concentration of NaCl (200 mmol/L). While plants treated with high concentration of NaCl (400 mmol/L) was little stilumated. The succulence of leaves was more obvious than that of expanding stems, while the expanded stems and roots were hardly succulent. The succulence extent of leaves and expanding stems reached a higher degree after 10 days treatment, while that of expanded stems decreased with treatment time.1.2 Effect of different salts on growth and succulence of seedingsDifferent salts had different effects on the growth and leaf succulence of 5. salsa. S. salsa could survive under other salts with exception of NaF. The succulent degree of leaves was the largest under NaCl. Succulent degree of expanded leaves was higher than that of expanding leaves. However, succulent degree of expanding leaves was markedly higher than that of expanded leaves under CaCl2. Succulent degree of the plants treated with Na2SO4 and KC1 were similar to controls. Succulent degree of MgCl2-treated leaves was lower than that of controls. The results showed different salts had different effects on the growth and succulence of S.salsa, and Na+plays a major role in the growth and succulence of S. salsa.1.3 Effect of isoosmotic PEG on succulence of seedingsSignificant difference was observed in the growth and succulence between 100 mmol/L NaCl and isoosmotic PEG. S. salsa seedlings withered at the third day under PEG treatment, the growth was significantly decreased, and succulent degree of shoots under PEG treatment was 0.47 times that of shoots under NaCl treatment. The results suggested that it was that ions (NaCl) not osmotic stress leading to succulence of S. salsa.2. Effect of salt treatment on ionic concentration and osmotic potential of cell sap of leaves2.1 Effect of salt treatment on ion concentration of cell sap of leaves2.1.1 Effect of NaCl treatment on ion concentration of cell sap of leavesThe concentrations of Na and Cl in the cell sap of leaves increased rapidly with the increase of NaCI concentration in medium, but the amounts of CI" were lower than those of Na+. The results showed S.salsa accumulated Na and CI" as osmotica.2.1.2 Effect of different salts treatment on ion concentration of cell sap of leavesThe concentrations of Na' in the cell sap of leaves were different under different salts treatment. The concentration of Na+ under salts containing Na+ was higher than that under other salts. The concentration of Na* under salts containing Na+ were followings: NaCl> Na2SO4) and NaHCO3.While the concentrations of Na under MgCl2 and CaCl2 were similar to controls. The concentration of CI" in the cell sap of leaves was different under different sails. The concentration of Cl- under salts containing Cl was higher than those under other salts. The concentration of CT under salts containing Cl were followings: KCl> MgCl2, CaCl2 and NaCl.2.2 Effect of salt treatment on osmotic potential of cell sap of leaves2.2.1 Effect of NaCI treatment on osmotic potential of cell sap of leavesDue to plants' obtaining a great deal of ions, the osmotic potential of NaCI treatment decreased with the increase of NaCl concentration in medium.2.2.2 Effect of treatment of different salts on osmotic potential of cell sap of leavesThe osmotic potential of leaf...