What if we could grow rice and wheat with the same amount of water and fertiliser but end up with 50 per cent more food? Sound like magic? Bad accounting? No, just some chemistry and genetic engineering. Scientists have recently figured out the second of three steps to make photosynthesis a whole lot more efficient in plants.
Plants are not, it turns out, perfectly efficient at making food out of thin air (turning carbon dioxide into sugars, to be more technical). And the vast majority of crops we eat use the slower of the two types of photosynthesis found in plants. If we could make the whole process more efficient, scientists estimate we could increase yields by 36 to 60 per cent, going a long way toward feeding the world’s booming population.
To do that, some researchers have turned to bacterial genes. Cyanobacteria are also photosynthetic, but they use a different — and more efficient — process than plants. The whole process as transplanted into tobacco plants has three steps, Kevin Bullis explains in Technology Review:
First, proteins form a special compartment within a plant cell that concentrates CO2; second, the compartment contains a speedy enzyme for converting that CO2; and third, the cells use special pumps in their membranes to usher CO2 into the cells.
Scientists have inserted these photosynthesis genes from cyanobacteria into tobacco, a common lab plant. The first step, forming a special compartment, was completed earlier this year, and now a new study in Nature describes how to pull off the second. To finish the job, scientists still have to figure out that last step and put all three together — getting maybe a dozen or so cyanobacteria genes to work perfectly in concert inside a plant cell.
Then there’s the formidable policy hurdles, which have held up potentially beneficial GM crops like golden rice. [Technology Review, Nature]
Picture: Tobacco plants being grown in Kentucky. AP Photo/Ed Reinke