Scientists transferred a gene from a C4 plant called Setaria italica into rice to improve photosynthesis. The gene increased the activity of an enzyme called PEPC in the rice plants. This led to better photosynthesis, more efficient water use, and higher yields in the genetically modified rice compared to regular rice. The modified rice plants were able to use light more effectively, leading to increased growth and biomass production. Overall, adding the C4 gene to rice improved its ability to capture and use carbon dioxide, resulting in better plant growth.