Abstract:

The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae (Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of ICE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature (0～-6 ℃) induces Ca²⁺ concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca²⁺ plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K⁺ content and the balance of Na⁺/Cl^-.

Key words: Antarctic ice microalga, X-ray microanalysis, inorganic ions, low-temperature adaptation