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A New Way of Making Supper
by Dr. E. Kirsten Peters
Mar 16, 2009 | 591 views | 0 0 comments | 6 6 recommendations | email to a friend | print
Dr. E. Kirsten Peters
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I take a personal interest in pickup trucks that can shut down half their cylinders to get better gas mileage when conditions permit. And I’ve studied the mechanics of hybrid cars that save braking energy to help power your vehicle a bit later in your journey.

Efficiency fascinates me.

But the efficiency of engines, as important as it is, pales in global significance to the basic efficiency of one piece of the living world.

Enormous business opportunities and satisfying meals both hinge on our ability to increase the efficiency of crops. And the good news is that researchers are working hard to greatly increase the efficiency of the most important staple crop the world has ever known.

Rice provides more than a fifth of all the calories we humans consume. It is more important to stomachs worldwide than wheat, corn, rye or even Big Macs. In short, more than 3 billion people depend on rice as their main source of food, including most of the world’s poor.

But it happens that the basic way rice converts sunlight to carbohydrates is not efficient. In fact, rice is about as inefficient in the plant world as my 1987 pickup is compared to the new trucks that can shut down half their cylinders.

The rubber meets the road in the world of plants as carbon in the air is taken up and transformed into carbohydrates via photosynthesis. The source of carbon for plants is carbon dioxide gas. Yes, that’s the famous greenhouse gas you’ve heard about, but it’s also a natural component of every breeze you’ve ever felt, one that’s crucial to all the plants around us. And from the point of view of plants, there isn’t nearly enough carbon dioxide in the air.

As it happens, rice photosynthesis converts carbon dioxide into food in a pretty inefficient manner. In contrast, corn is a great example of a plant that makes much more efficient use of limited resources – including moisture in the soil and also carbon dioxide in the air. Corn’s internal processes are up to 50% more efficient than those of rice.

Plant scientists call corn a “C4” plant compared to the “C3” status of rice. Don’t sweat the names – I mention them only because you may see them on the business pages of your newspaper. But focus on this important point: corn can actively accumulate relatively scant carbon dioxide in a way that supercharges its photosynthesis engine. So corn powers right by rice on the crucial racetrack of converting sunlight into food.

A number of research scientists now have projects underway to help create a new strain of rice that runs on corn’s internal C4 biochemistry. It’s like putting a modern and efficient truck engine into my 1987 pickup. This kind of highly promising work is part of the emerging realm of biotechnology.

It’s not as easy to see the biotechnology in the world around us as it is to see the Internet and cell phones that clamor for our attention. But re-engineering the living world has potentially even more positive impact than improving electronics and engines.

Professor Gerry Edwards of Washington State University is one scientist dedicated to understanding the fundamentals of photosynthesis and the possibility of implanting the basic C4 engine into a C3 crop like rice. Under the leadership of the International Rice Research Institute in the Philippines, and through a grant funded by the Bill and Melinda Gates Foundation, Edwards is part of an international team at work on the project.

“C4 rice could yield more harvest on the same amount of land with increased efficiency in use of sunlight, fertilizer, and water. It’s especially important considering global warming and water shortages,” Edwards said to me recently. “C4 rice will require some years to achieve, but it’s definitely worth the effort.”

American researchers have always excelled at this kind of fundamental science, work that can make great leaps with practical benefits of consequence to billions of people. Research in science and engineering has been an economic powerhouse for us, and I’m sure it will contribute substantially to our recovery from this recession.

Pass the rice, please, and keep the good science coming.

Dr. E. Kirsten Peters is a native of the rural Northwest, but was trained as a geologist at Princeton and Harvard. Questions about science or energy for future Rock Docs can be sent to epeters@wsu.edu. This column is a service of the College of Sciences at Washington State University.

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