| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1985: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
Seedlings of a coastal halophyte, Atriplex gmelini C.A.Mey were grown in water culture with varying concentrations and species of salts. Plants receiving nutrients supplemented with 50mM NaCl gave the maximum dry weight yield compared with those receiving the higher or the lower concentrations of NaCl. Addition of 50mM KCl, 25mM <Na_2SO_4> , or 25mM <K_2SO_4> to the basal culture solution also stimulated the growth to the same extent. However, higher concentrations of potassium salts, such as than sodium salts did. At a concentration of 250 mM NaCl or KCl addition, the KCl-treated than sodium salts did. At a concentration of 250 mM NaCl or KCl addition, the KCl-treated plants showed a higher sodium plus potassium concentration than the NaCl-treated plants. This phenomenum may be ascribed to the lack of control systems for the maintenance of the internal concentration of potassium, which can operate when sodium salts are supplied.
Vacuoles were isolated via protoplasts from the leaves of a halophyte Atriplex gmelini C.A.Mey., grown in culture solution supplemented with 250 mM NaCl. Lysis of the protoplasts was induced by lowering the medium osmolarity and adding a detergent, a synthesized cholate derivative, CHAPS, at a concentration of 0.5 mM and the resulting vacuoles were purified by successive dilution and floatation. Isolated vacuoles contained almost the same concentration of sodium (569 mM) and chloride (260 mM) as recorded in protoplasts (582 mM and 254 mM, respectively), suggesting that the vacuoles are the major sequestration site of NaCl in leaves of halophytes. Betaine concentration in the protoplasts was about 16 mM, while that in vacuoles was only about 0.24 mM, indicating that betaine is accumulated in the cytoplasm as compatible solute.
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