Discovery delivers high starch content, virtually no methane
emissions
(July 29, 2015) Rice
serves as the staple food for more than half of the world's population, but
it's also the one of the largest manmade sources of atmospheric methane, a
potent greenhouse gas. Now, with the addition of a single gene, rice can be
cultivated to emit virtually no methane from its paddies during growth. It also
packs much more of the plant's desired properties, such as starch for a richer
food source and biomass for energy production, according to a study in Nature.
With their warm, waterlogged soils, rice paddies contribute
up to 17 percent of global methane emissions, the equivalent of about 100
million tons each year. While this represents a much smaller percentage of
overall greenhouse gases than carbon dioxide, methane is about 20 times more
effective at trapping heat. SUSIBA2 rice, as the new strain is dubbed, is the
first high-starch, low-methane rice that could offer a significant and
sustainable solution.
Researchers created SUSIBA2 rice by introducing a single
gene from barley into common rice, resulting in a plant that can better feed
its grains, stems and leaves while starving off methane-producing microbes in
the soil.
The results, which appear in the July 30 print edition of
Nature and online, represent a culmination of more than a decade of work by
researchers in three countries, including Christer Jansson, director of plant
sciences at the Department of Energy's Pacific Northwest National Laboratory
and EMSL, DOE's Environmental Molecular Sciences Laboratory. Jansson and
colleagues hypothesized the concept while at the Swedish University of
Agricultural Sciences and carried out ongoing studies at the university and
with colleagues at China's Fujian Academy of Agricultural Sciences and Hunan
Agricultural University.