| Potassium is one of the three major plant nutrient elements which exists in ionic formin cells with high concentration. The intimate connection between K4 and Na4 was the determinant of the salt tolerance of plants. In this experiment salt-dilution halophyte S. salsa treated with I( and Na4, was studied on the physiological indices and activity of tonoplast H4-ATPase and W-PPase and the western-blotting results of W-ATPase and W-PPase were analysed. The results were shown as follows:1. Effect of K4 and NaC1 treatment on growth of seedlings of S. sa/saEffect of salinity on the growth of seedlings of S. salsa depended on K4 concentmtionin the root medium. The growth rate, fresh weight and diy weight of shoots, roots and whole plants could be increased by the increase of K4 concentration. Except for the condition of extremely low K4 supply in root medium, the diy weight of shoots, roots and whole plants were greatly increased by the treatment of NaCI. If the K4 supply was exlremly low, there was a little increase of dxy weight of shoots and whole plants under 100 mM NaC1 treatment; while when exposed to 400 mM NaCI, the dxy weight of shoots or the whole plants reduced markedly.The root/shoot ratio of S.salsa was distinctively different from that of unhalophytes.On base of fresh weight; the root/shoot ratio was decreased rather than increased by NaC1 treatment Whatsmore, the root/shoot mtio was decreased with the increase of K4 concentmtion(from0to0.i mMwithlowK4supplyand from ito 6mMwithhighK4 supply) at any IC concentration in the root medium. There was no signillcant difference (P>0.05) hi root/shoot ratio between control and NaCI treated plants.2.Effect of K4and Naireainient on the content and distribution of K4 and Na4 in leaves and roots of S. salsa.The K4 content in leaves was not affected by IC and Na4 supplied to root medium when plants were exposed to 0 or 100 mM NaC1 and the K4 concentration in the roots medium was low (0 mM, 0.1 mM). But when they were exposed to high NaCI concentration such as 400 mM, K4 content in leaves was slightly decreased. K4 supplied56to root was relative higher (1 mM, 6mM), the K content and K/Na ratio increased with the increase of K supplied to root medium, but decreased with the increase ofNaCl concentration, while Na and Ct content in leaves increased with the increase of NaCl concentration. K content in roots also increased with the increase of K concentration and decreased with the increase of NaCl concentration at any level of IC and Na treatmentThe increase of K concentration under condition of low level of K (0mM, 0.1 mM)had little influence on the distribution of K in leaves and roots. The increase of IC concentration under condition of high level of IC (1 mM, 6mM) increased IC distribution. The distribution of Na in the leaves and roots was little affected by the changes of K, Na concentration in root medium under NaCl treatment There was a distinctive competence between K and Na in leaves or roots. The higher concentration Ksupplied to the root medium (0mM to 0.1 mM at low level ofK, 1mM to 6mM at low level of K), the more the relative percentage content of IC in leaves, the less relative percentage content of Na in the leaves. Clearly, changes of K and Na concentration in leaves and roots did not represent a simple one for one replacement of IC by Na, and the patterns of distribution, accumulation and transportation of IC and Nadiffer under low K0 mM, 0.1 mM and high K1 mM, 6mM concentration in the root medium.3.Efié‘“t of solutes.on osmotic adjusUnent of S. salsa under IC, Na treaUnentThe major osmotic solution is K in the control leaves under the condition of high level of IC (1 mlvi, 6mM) in the root medium. Under the condition of low level of K (0 mM, 0.lmlvl) the root medium, the major osmotic solute is Na, K is in the secondazy place. In the NaC1 treated leaves, Na and Cl were used as the major osmosolute at any level of K supplied... |
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