Changes in Gene Expression from Diploid to Autotetraploid Status of Lycopersicon esculentum

The activity levels of enzymes involved in photosynthesis, respiration and nitrogen metabolism were evaluated in a diploid and in the derived autotetraploid Lycopersicon esculentum. The autotetraploid exhibited, compared to the diploid, higher protein and reduced dry matter content; reduced rate of protein synthesis; enhanced activity of malate dehydrogenase, acid invertase, glutamate dehydrogenase, and nitrate reductase; decreased peroxidase activity; unchanged polymorphism of the above‐listed enzymes as revealed by electrofocusing, namely reduced CO2 fixation caused by lower ribulose‐1‐5‐diphosphate carboxylase and even lower phosphoenolpyruvate carboxylase activities in accordance with a smaller contribution of the C4 carboxylating cycle; lower activities of the two “key” enzymes of photorespiration ribulose‐1‐5‐diphosphate oxygenase and glycolate oxydase. The results suggest that the gene expression of the double gene dosage is enhanced in some cases and depressed in others, resulting in more unfavourable balance of the metabolic settlement.