title: Optimizing rice plant photosynthate allocation reduces N2O emissions from paddy fields.
abstract: Rice paddies are a major source of anthropogenic nitrous oxide (N2O) emissions, especially under alternate wetting-drying irrigation and high N input. Increasing photosynthate allocation to the grain in rice (Oryza sativa L.) has been identified as an effective strategy of genetic and agronomic innovation for yield enhancement; however, its impacts on N2O emissions are still unknown. We conducted three independent but complementary experiments (variety, mutant study, and spikelet clipping) to examine the impacts of rice plant photosynthate allocation on paddy N2O emissions. The three experiments showed that N2O fluxes were significantly and negatively correlated with the ratio of grain yield to total aboveground biomass, known as the harvest index (HI) in agronomy (P < 0.01). Biomass accumulation and N uptake after anthesis were significantly and positively correlated with HI (P < 0.05). Reducing photosynthate allocation to the grain by spikelet clipping significantly increased white root biomass and soil dissolved organic C and reduced plant N uptake, resulting in high soil denitrification potential (P < 0.05). Our findings demonstrate that optimizing photosynthate allocation to the grain can reduce paddy N2O emissions through decreasing belowground C input and increasing plant N uptake, suggesting the potential for genetic and agronomic efforts to produce more rice with less N2O emissions.
authors.affiliation: Institute of Applied Ecology, Nanjing Agricultural University, Nanjing 210095, China.|Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Institute of Applied Ecology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences / Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing 100081, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: The High School Affiliated to Renmin University of China, Beijing 100080, China.
authors.forename: Xingyue
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Applied Ecology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences / Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing 100081, China.
authors.forename: Chengyan
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences / Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing 100081, China.
authors.forename: Aixing
authors.initials: A
authors.lastname: Deng
authors.affiliation: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences / Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing 100081, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK.
authors.forename: Lianhai
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Shuijin
authors.initials: S
authors.lastname: Hu
authors.affiliation: Institute of Applied Ecology, Nanjing Agricultural University, Nanjing 210095, China.|Institute of Crop Sciences, Chinese Academy of Agricultural Sciences / Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing 100081, China.
authors.forename: Weijian
authors.initials: W
authors.lastname: Zhang
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism; D002523:Edible Grain / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D060847:Metabolic Engineering; D009584:Nitrogen / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism*; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010788:Photosynthesis; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D002244:Carbon; D009609:Nitrous Oxide; D009584:Nitrogen