DAY-NIGHT CHANGES OF THE AMOUNT OF SUBUNIT-C TRANSCRIPT OF THE V-ATPASE IN SUSPENSION CELLS OF MESEMBRYANTHEMUM-CRYSTALLINUM L

Day-night oscillations of the V-ATPase subunit-c transcript amount pre viously observed in mature leaves of Mesembryanthemum crystallinum L. also occur in photoautotrophic suspension cells. Thus, oscillations of subunit-c transcript amounts are an intrinsic trait of M. crystallinu m cells. Speculations are discussed, if the putative enhancement of th ese oscillations by day-night changes of turgor in the cells of intact leaves and their actually demonstrated enhancement by salinity might be involved in a trigger mechanism leading to the switch from Cc-photo synthesis to CAM in stressed plants of M. crystallinum.