As. Mostaert et al., ION COMPARTMENTATION IN THE RED ALGA CALOGLOSSA-LEPRIEURII IN RESPONSE TO SALINITY CHANGES - FREEZE-SUBSTITUTION AND X-RAY-MICROANALYSIS, New phytologist, 132(3), 1996, pp. 513-519
The elemental content of cell compartments in the euryhaline red macro
alga Caloglossa leprieurii (Montagne) J. Agardh subjected to different
salinities, was determined by X-ray microanalysis of freeze-substitut
ed thin sections. Data are given for three compartments; cell wall, va
cuole and cytoplasm. The most abundant elements detected were potassiu
m, sodium and chlorine, with a sulphur peak in the cell wall indicatin
g the presence of sulphated polysaccharides. With salinity upshock the
cytoplasm is maintained low in K, Na and Cl, whereas in the vacuoles
they increased. High levels of K and Na located in the cell wall refle
ct cation binding to negatively charged polysaccharides. Hyposaline sh
ock resulted in decreased K, Na and Cl levels in all compartments, tho
ugh K was retained in the cytoplasm. Results are discussed with regard
to the role of ion compartmentation in the salt tolerance of this alg
a, and the cation exchange properties of the cell wall are emphasized.