RUBISCO,ALTERED ACTIVITY AND AMOUNTS OF A DAYTIME TIGHT-BINDING INHIBITOR IN TRANSGENIC TOBACCO EXPRESSING LIMITING AMOUNTS OF PHOSPHORIBULOKINASE

Transgenic tobacco with RuBP-limited photosynthetic assimilation due t o a 95% reduction in phosphoribulokinase activity, had higher specific activities of Rubisco in fresh extracts and after full activation, th an in the wild type. Differences in the amounts of a daytime tight-bin ding inhibitor were sufficient to contribute significantly to these ac tivity differences.