Oxford project to multiply rice production enters new stage

A project seeking to improve photosynthesis in rice is continuing to show promise for increasing crop yields and feeding the world’s hungry.

The C4 Project is based on the fact that rice uses the C3 photosynthetic pathway, but scientists from Oxford University are trying to develop a way for rice to use the C4 photosynthetic pathway that maize and sorghum use. That could increase productivity by 50 percent. In addition, if rice used the C4 method, it could improve nitrogen-use efficiency, double water-use efficiency, and increase tolerance to high temperatures.

The C4 Project will help the approximately 1 billion people who live in hunger, especially in South Asia and sub-Saharan Africa. The food supply in these areas is primarily provided by small-holder farmers who would be able to make more crops and therefore more money.

Professor of Plant Development Jane Langdale from Oxford's Department of Plant Sciences, is the principal investigator on Phase III of the C4 Rice Project.

"Over 3 billion people depend on rice for survival, and, owing to predicted population increases and a general trend towards urbanization, land that currently provides enough rice to feed 27 people will need to support 43 by 2050," she said. "In this context, rice yields need to increase by 50 percent over the next 35 years.

"Given that traditional breeding programs currently achieve around a 1 percent increase in yield per annum, the world is facing an unprecedented level of food shortages. The intrinsic yield of rice, a C3-type grass, is limited by the inherent inefficiency of C3 photosynthesis. Notably, evolution surmounted this inefficiency through the establishment of the C4 photosynthetic pathway, and importantly it did so on multiple independent occasions. This suggests that the switch from C3 to C4 is relatively straightforward.

"As such, the C4 program is one of the most plausible approaches to enhancing crop yield and increasing resilience in the face of reduced land area, decreased use of fertilizers, and less predictable supplies of water.”