ISSN:
1615-6102
Keywords:
Chlamydomonas
;
Accumulation
;
Purines
;
Vacuole
;
Xanthine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Utilization of xanthine as the sole nitrogen source for growth byChlamydomonas reinhardtii cells involved the formation of a transient, intracellular pool of xanthine. Up to 20% of the total xanthine supplied to the medium was not assimilated after uptake but stored in the cells at concentrations that exceeded xanthine solubility in water. At the subcellular level, a massive accumulation of starch grains in the chloroplast and the appearance of many vacuoles in the cytoplasm distinguished xanthine-grown from ammonium-grown cells. Starch accumulation, but not development of vacuoles, was also observed in N-starved cells. Uptake experiments with radio-labelled xanthine showed that this accumulates only in the cytoplasm, most probably inside vacuoles. The electron-dense material observed in vacuoles of xanthine-grown cells suggests that the intracellular xanthine is in part solid xanthine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01276941
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