Photosynthesis improvement for enhancing productivity in rice
Amane Makino
Abstract
The success of the dwarf breeding of rice and wheat, called the Green Revolution, was due to increased source and sink capacities, which depended on large increases in N fertilizer inputs. However, today’s high N fertilization has an extremely large impact on the environment. While there have been disputes as to whether photosynthetic improvement leads to an increase in crop yields, transgenic rice overproducing ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) – the key enzyme of photosynthesis, has shown increased yields with improved N-use efficiency for increasing biomass production when receiving sufficient N fertilization in an experimental paddy field. A large-grain cultivar, Akita 63 had high yield potential without improvement of source, with yield analysis suggesting that enhancement of photosynthesis would be of the greatest importance for further increases in the yield of high-yielding cultivars with improved N use efficiency. Development of innovative rice plants with high photosynthetic capacity and large sink is required.