Why C4 Rice

Problem and Urgency

Currently, a billion people live on less than a dollar a day and spend half their income on food, 854 million people are hungry and each day about 25000 people die from hunger-related causes. 


Sixty percent of the world’s population lives in Asia where each hectare of land used for rice production currently provides food for 27 people, but by 2050 that land will have to support at least 43 people. Climate change will likely result in more extreme variations in weather and cause adverse shifts in the world’s existing climatic patterns. Water scarcity will grow. The increasing demand for biofuels will result in competition between grain for fuel and grain for food, resulting in price increases. Furthermore, more than 75% of the world’s people will live in cities, whose populations will need to be largely supported by a continuous chain of intensive food production and delivery. However, growth in production is slowing. The elite rice cultivars, which dominate the food supplies of the millions of poor people in Asia, have approached a yield barrier, plant breeding seems to have exploited all of the intrinsic high yield-linked genes Ultimately insufficient yields of rice produce food insecurity, unsustainable agricultural practices, environmental degradation and social unrest This vicious cycle must be replaced by a virtuous cycle where raised productivity improves food security so that investments in sustainable agriculture are attractive; then the environment is protected.


The Solution

What technology could simultaneously solve those problems and prevent the bleak future outlined above from becoming a reality? Innovative research at IRRI suggested that the solution to the challenges ahead for rice would require solar energy to be used more efficiently in photosynthesis.Fortunately, there is one example from evolution of a supercharged photosynthetic mechanism; the C4 system. 

Converting the photosynthetic system in rice to the more efficient, supercharged C4 one used by maize would increase rice yields while using scarce resources (land, water, fertilizer) more effectively.However a technological innovation of this magnitude requires the skills and technologies of a global alliance of multidisciplinary partners from advanced institutions. In 2008, IRRI formed the International C4 Rice Consortium.