In December, geneticists announced that they’d made a major advance in engineering rice plants to carry out photosynthesis in a more efficient way—much as corn and many fast-growing weeds do. The advance, by a consortium of 12 laboratories in eight countries, removes a big obstacle from scientists’ efforts to dramatically increase the production of rice and, potentially, wheat. It comes at a time when yields of those two crops, which together feed nearly 40 percent of the world, are dangerously leveling off, making it increasingly difficult to meet rapidly growing food demand.
The supercharged process, called C4 photosynthesis, boosts plants’ growth by capturing carbon dioxide and concentrating it in specialized cells in the leaves. That allows the photosynthetic process to operate much more efficiently. It’s the reason corn and sugarcane grow so productively; if C4 rice ever comes about, it will tower over conventional rice within a few weeks of planting. Researchers calculate that engineering C4 photosynthesis into rice and wheat could increase yields per hectare by roughly 50 percent; alternatively, it would be possible to use far less water and fertilizer to produce the same amount of food.