CHENNAI - International agricultural scientists will work for a new Green Revolution (GR) in rice on the knowledge they have acquired through the genomics of rice and the rice plant. The new revolution is targeting the engine of rice, photosynthesis.

The radically new international scientific effort was launched last week at the Manila, the Philippines-based International Rice Research Institute (IRRI).

The new system aims to improve the photosynthetic efficiency of the rice plant to give a better yield. Scientists believe that with the understanding of the gene sequence of rice and with all the new knowledge they have about the rice plant, it could be done.

According to an IRRI report, scientists have been working on different aspects of the approach since the early 1990s. The new knowledge generated by the sequencing of the rice genome is allowing researchers for the first time to discuss how they might work together to completely reconfigure what is known as the engine of rice production, the plant's photosynthetic system, the report says.

"If you think of the rice plant as a car, what we were talking about is really supercharging the engine," said IRRI crop ecologist John Sheehy, convener of a workshop on 'C4 Rice - Supercharging the Rice Engine', at the institute.

"The photosynthetic process is the engine of growth for the rice plant, so, if we can improve that, then the whole plant benefits. If we continue with the car analogy, the GR of the 1960s and 1970s focused on providing a new, more compact body for the rice plant," Sheehy added.

The focus is on enhancing the rice plant's photosynthetic efficiency, ie, converting rice from a 'C3' plant to a 'C4' plant, where the 'C' refers to the carbon captured by photosynthesis for growth. 'C4' plants-such as maize-utilise solar energy more effectively.

"If we can successfully develop a 'C4' rice plant, the implications and potential impact will be huge - it is one of the great scientific challenges facing people working in the plant sciences," Sheehy said.

The experts at the workshop suggested that it will probably take another three to four years to achieve the 'proof-of-concept' needed before an international consortium of scientists could assemble the tools and materials to begin constructing the prototypes of a 'C4' rice plant. It will be another 10 to 15 years before the first varieties are available. "Considering the rice production challenges we face, we must start now on this work," Sheehy said.

IRRI played a pivotal role, right from the 1960s, in introducing and promoting high-yielding, high input rice varieties around the world.