A new type of genetically modified rice could be a double whammy – helping to tackle hunger and climate change all at the same time. By inserting a chunk of DNA taken from barley, the rice plant has a higher yield, while also emitting as little as 1% of the methane of conventional rice varieties. The results are published in Nature.
Interestingly, the production of rice is responsible for between 7-17% of all human-induced methane emissions, and as methane is a powerful greenhouse gas, it is thus not an insubstantial contributor to climate change. Most of this methane is actually produced by microbes that live in the rice paddies, feeding on sugar that is released by the rice plants through their roots. By inserting a gene into the plants that make them store more of this sugar in their stems and grain, the scientists managed to dramatically cut this emission, while simultaneously increasing the starch content of the grain.
It’s been known for a while that rice paddies release lots of methane, and other techniques have tried to limit this. One of the major changes made to rice agriculture has been to stop draining the fields multiple times a year, and only doing it once. This change in practice was able to limit the growth of the methane-producing bacteria, and drastically reduced methane emissions. Even so, the issue still persists.
Once the microorganisms feast on the sugar that the plants release, the bacteria produce methane, which then goes into the water in the paddies. Most of this is then absorbed by the rice plants and released through their leaves. It was in 2002 that scientists first noticed that those rice plants that produced more grain also emitted less methane.
But there are problems. The scientists, from the Swedish University of Agricultural Sciences, say that China simply isn’t ready for GMO crops, and that no GM rice varieties have been licensed to be grown in the country. So now they’re looking instead at ways to breed the exact same genetic change into the rice by more traditional techniques such as selective breeding. The results of this would be no different to the GM variety, just that the researchers say it might take an additional ten years.
Others have, however, expressed concern about the changes this plant might have on the long-term health of the soil by changing the ecosystem, something which no one can predict the results of. Another worry is that because there will be less carbon leaching into the soil in the form of sugars, farmers might have to use more fertilizer to get the increase in yield, which then has all sorts of other impacts on the environment.