* Permanent address: Department of Botany, Faculty of Science, Assiut University, Assiut, Egypt.
The fresh water green alga ChlorellaPyrenoidosa synthesizes and degrades proline in response to increasing and decreasing NaCl concentrations, respectively. This synthesis and degradation of proline is essentially light independent, however, both of these processes are inhibited by high concentration (20µM) of uncoupler carbonyl cyanide P-trifioromethyl (CCCP). Lower concentrations (10µM) of CCCP inhibit proline synthesis and degradation when cells were incubated in the dark after hypertonic or hypotonic stresses respectively. This inhibition is relieved by light. However, proline synthesis and degradation were suppressed by the ATP ase inhibitor tri-n-butyl tin chloride (TNBT) suggesting dependence of proline synthesis and degradation on ATP.
