The green revolution’s breeding of semi-dwarf rice cultivars in the 1960s improved crop yields, with large increases in the use of nitrogen (N) fertilizer. However, excess N application has caused serious environmental problems, including acid rain and the eutrophication of rivers and oceans. To use N to improve crop yields, while minimizing the associated environmental costs, there is a need to produce crops with higher N-use efficiency and higher yield components. Here we show that transgenic rice overproducing ribulose 1,5-bisphosphate carboxylase–oxygenase (Rubisco)—the key enzyme of photosynthesis—exhibits increased yields with improved N-use efficiency for increasing biomass production when receiving sufficient N fertilization in an experimental paddy field. This field experiment demonstrates an improvement in photosynthesis linked to yield increase due to a higher N-use efficiency in a major crop. Transgenic rice engineered to increase photosynthetic activity through overproduction of ribulose 1,5-bisphosphate carboxylase–oxygenase (Rubisco) shows increased rice yields, with improved nitrogen-use efficiency, in an experimental paddy field.
