The genetic basis and improvement of photosynthesis in tomato

Photosynthesis is one the most important chemical reaction in plants, and it is the ultimate energy source of any living organisms. The light and dark reactions are two essential phases of photosynthesis. Light reaction harvests light energy to synthesize ATP and NADPH through an electron transport chain, and as well as giving out O2; dark reaction fixes CO2 into six carbon sugars by utilizing NADPH and energy from ATP. Subsequently, plants convert optical energy into chemical energy for maintaining growth and development through absorbing light energy. Here, firstly, we highlighted the biological importance of photosynthesis, and hormones and metabolites, photosynthetic and regulating enzymes, and signaling components that collectively regulate photosynthesis in tomato. Next, we reviewed the advances in tomato photosynthesis, including two aspects of genetic basis and genetic improvement. Numerous genes regulating tomato photosynthesis are gradually uncovered, and the interaction network among those genes remains to be constructed. Finally, the photosynthesis occurring in fruit of tomato and the relationship between photosynthesis in leaf and fruit were discussed. Leaves and fruits are photosynthate sources and sinks of tomato respectively, and interaction between photosynthesis in leaf and fruit exists. Additionally, future perspectives that needs to be addressed on tomato photosynthesis were proposed.