THE INFLUENCE OF PLANT PYRUVATE, ORTHOPHOSPHATE DIKINASE ON A C-3 PLANT WITH RESPECT TO THE INTRACELLULAR LOCATION OF THE ENZYME

We produced transgenic tobacco plants expressing the plastidic pyruvat e, orthophosphate dikinase (PPDK) from the facultative Crassulacean ac id metabolism plant Mesembryanthemum crystallinum. These transgenic pl ants had increased PPDK amounts in leaves and seeds. They produced mor e seeds per seed capsule and heavier seed capsules than the wildtype. When the enzyme was expressed in the cytosol by deleting the plastid s ignal sequence the transgenic tobacco plants produced less seeds than the wildtype and the transgenic line with the strongest phenotype prod uced nearly no seeds at all. All transgenic tobaccos were different th an the wildtype with respect to the pattern of free amino acids in see ds and sink- and source leaves but not in roots. (C) 1998 Elsevier Sci ence Ireland Ltd. All rights reserved.