Friday, June 6, 2014, 09:43
In search of a new strain of super rice
By Karl Wilson

In search of a new strain of super rice
A villager separates rice grains at harvest time near Lahore, Pakistan. Around 90 percent of the world’s rice is grown and consumed in Asia, and billions of people in the region depend on it as their main source of nutrition. (AFP)
Just outside the Philippine capital amid the lush rolling hills of Los Banos, some of the world’s leading scientists are working on a project that they hope will produce a revolutionary high-yielding rice strain that will ensure future global supply for the daily staple that feeds almost half the world’s population.

Known as the C4 Rice Consortium, the project employs some of the world’s finest scientific minds to try and change the biology of the rice plant from what is known as C3 into C4.

If the scientists manage to crack the gene code they will not only have revolutionized biology, they will have improved the lives of billions of people who rely on rice as their main source of nutrition.

It has been estimated that 90 percent of the world’s rice is grown and consumed in Asia.

So important is the work that much of the funding is being done through the Bill and Melinda Gates Foundation, who saw the project as a major contributor to global food security.

Much of the work is concentrated at the International Rice Research Institute (IRRI) at Los Banos where its director, Robert Zeigler, once described the project as being a “bit like the Apollo (space) project — long range, high risk, but with an extremely high pay off”.

It also involves some of the world’s leading research centers: Oxford and Cambridge universities in the UK; Yale and Cornell universities in the United States; the CSIRO — the Commonwealth Scientific and Industrial Research Organisation — and the Australian National University in Australia.

Finding the gene that can crack the code is the challenge, says Robert Furbank, research group leader with the CSIRO and one of the country’s leading researchers on photosynthesis.

With so many people dependent on rice, especially in Asia, this research is seen as vital for ensuring the continued supply of the cereal and to prevent mass starvation as the world’s population increases and climate change impacts on traditional growing areas.

According to a recent report in The Economist, with every 1 billion growth in the world population, an extra 100 million tons of rice will be needed to feed them.

“Given current world-population forecasts, total rice consumption, now under 450 million tons, is likely to grow to 500 million tons a year by 2020 and to 555 million tons by 2035 — an increase of 1.2 to 1.5 percent a year,” the report said.

“That would be manageable if rice yields were also growing at that rate. But they are not. They are rising at barely half that pace.”

During the first so-called Green Revolution in the 1950s and 1960s, new, high-yielding varieties of rice saw production rise from 2 tons a hectare to 3.5 tons — but this only just managed to keep pace with population growth.

What we see today are yields stalling and in some places they are falling. And with the population expected to grow by 2 billion by 2050, the job of feeding them becomes critical as most of them will be in Asia.

Climate change is already having an impact on rice production.

Some 65 percent of the world’s rice comes from the great deltas of Asia such as the Mekong and Bangladesh. Both these areas will be massively impacted if sea levels rise, which they are predicted to do as the planet heats up.

Throughout Asia, especially in China, thousands of hectares of good agricultural land is being taken out of production annually for urban and industrial development, placing pressure on the land that is left for agriculture.

In Asia, for example, each hectare of land used for rice production currently provides food for 27 people. By 2050, that land will need to support at least 43 people.

The achievements of the Green Revolution showed farmers how to improve their rice production and increase yields. But it had its limitations and there is very little that can be done to increase yields with the varieties of rice now available.

If the C4 project is a success, the new variety of rice will need less water and fertilizer but yield 50 percent more grain than the best current varieties.

The science is complex and involves changing the biophysical structure of the rice plant, making it a much more efficient user of energy from the sun.

Plants use solar radiation to grow — to develop leaves, roots, stems, flowers, and seeds — in a process known as photosynthesis.

Rice has what is known as a C3 photosynthetic pathway. This is less efficient than those of maize, sugar cane or sorghum, which have a C4 pathway. The goal is to genetically modify rice into a C4 photosynthesis plant so it can absorb sunlight faster, use less water and require less fertilizer.

Some 83 percent of plant species are C3, including wheat, rice, barley and oats, which provide some of the basic nutrients that sustain life.

According to Furbank, the CSIRO has had a long history with the project.

“In fact it was at the CSIRO that the C4 pathway was first discovered in the 1960s,” he tells China Daily Asia Weekly.

“So there is an historic link, if you like, as well as our current research in this field.”

He explains the C4 project came about with the realization that, in terms of rice, we had reached the point that the improvements made during the Green Revolution in terms of yield were largely exhausted.

“We first workshopped this at IRRI over 10 years ago and sat around throwing out ideas on how we could bump up yields. One answer was to try and turbocharge the plant’s photosynthetic engine.

“In other words, re-engineer the photosynthetic engine of the rice plant.”

An article in the science magazine Cosmos last year said that in the “age of genetic engineering, one straightforward approach is to transfer the 12 or so ‘turbocharging’ genes that the corn plant evolved for this purpose into a rice plant. But the problem is finding the right genes in a pool of thousands.

“In 2000, Maurice Ku at Washington State University tried but didn’t get far. Part of the reason is you cannot just dump the components of the C4 engine into rice — it has the wrong infrastructure.

“Imagine trying to fit a Ferrari engine into a VW (Volkswagen). For starters the Ferrari engine won’t fit, and the VW is designed to operate with different suspension, engine mountings and exhaust system. Same problem with rice: The engineers have to redesign the plant’s infrastructure, a tough order.”

Furbank acknowledges the huge challenges that the project will face.

“It’s not an easy job,” he says. “This is the only project I know of in plant biology that is truly global and captures a large proportion of the world’s experts.

“Last count, there were 11 laboratories and 16 countries working on this. It is a big deal, especially when you wrap it around the importance of global food security.”

Furbank recalls Robert Zeigler, director of IRRI “throwing some figures” at him that he found astonishing.

“He said something like 30 percent of people in Asia spent 40 percent of their income just on rice. There is a real knife edge balance in terms of supply and demand which at any time can challenge the ability of these people to feed themselves.”

Furbank illustrates his point with the example of a few years ago when the price of rice shot up from $350 a ton to $700.

“It didn’t have much impact on the first world,” he says, “but if you are spending 40 percent of your income on rice in the developing world then you have a problem.”