title: Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice.
abstract: Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7-17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25-100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement. Despite proposed strategies to increase rice productivity and reduce methane emissions, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2 (refs 7, 8), conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased methane emissions from paddies.
authors.affiliation: 1] Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China [2] Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO Box 7080, SE-75007 Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Su
authors.affiliation: 1] Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China [2] Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO Box 7080, SE-75007 Uppsala, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Hu
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO Box 7080, SE-75007 Uppsala, Sweden.
authors.forename: X
authors.initials: X
authors.lastname: Yan
authors.affiliation: 1] Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO Box 7080, SE-75007 Uppsala, Sweden [2] Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha 410128, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Guan
authors.affiliation: Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhong
authors.affiliation: The Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory, PO Box 999, K8-93 Richland, Washington 99352, USA.
authors.forename: C
authors.initials: C
authors.lastname: Jansson
authors.affiliation: Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Uppsala BioCenter, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Schnürer
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO Box 7080, SE-75007 Uppsala, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Sun
mesh_terms: D000383:Agriculture / Q000379:methods / Q000639:trends; D001272:Atmosphere / Q000737:chemistry; D018533:Biomass; D057486:Carbon Cycle; D002681:China; D003247:Conservation of Natural Resources / Q000379:methods; D005523:Food Supply / Q000379:methods; D005838:Genotype; D057232:Global Warming / Q000517:prevention & control; D017752:Greenhouse Effect / Q000517:prevention & control*; D001467:Hordeum / Q000235:genetics*; D008697:Methane / Q000096:biosynthesis / Q000378:metabolism*; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010641:Phenotype; D010788:Photosynthesis; D035261:Plant Components, Aerial / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified; D058441:Rhizosphere; D012639:Seeds / Q000378:metabolism; D013213:Starch / Q000096:biosynthesis / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D013213:Starch; D008697:Methane