title: Wheat ear carbon assimilation and nitrogen remobilization contribute significantly to grain yield.
abstract: The role of wheat ears as a source of nitrogen (N) and carbon (C) in the grain filling process has barely been studied. To resolve this question, five wheat genotypes were labeled with15N-enriched nutrient solution. N remobilization and absorption were estimated via the nitrogen isotope composition of total organic matter and Rubisco. Gas exchange analyses showed that ear photosynthesis contributed substantially to grain filling in spite of the great loss of C due to respiration. Of the total kernel N, 64.7% was derived from the N acquired between sowing and anthesis, while the remaining 35.3% was derived from the N acquired between anthesis and maturity. In addition, 1.87 times more N was remobilized to the developing kernel from the ear than from the flag leaf. The higher yielding genotypes showed an increased N remobilization to the kernel compared to the lower yielding genotypes. In addition, the higher yielding genotypes remobilized more N from the ears to the kernel than the lower yielding genotypes, while the lower yielding genotypes remobilized more N from the flag leaf to the kernel. Therefore, the ears contribute significantly toward fulfilling C and N demands during grain filling.
authors.affiliation: Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, China.|Unit of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Bangwei
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Unit of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Maria Dolores
authors.initials: MD
authors.lastname: Serret
authors.affiliation: Unit of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Abdelhalim
authors.initials: A
authors.lastname: Elazab
authors.affiliation: Unit of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Bort Pie
authors.affiliation: Unit of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Araus
authors.affiliation: Agrobiotechnology Institute, Public University of Navarra-CSIC-Navarra Government, Arrosadia Campus, E-31192-Mutilva Baja, Spain.
authors.forename: Iker
authors.initials: I
authors.lastname: Aranjuelo
authors.affiliation: Unit of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain. alvaro_ssj@hotmail.com.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Sanz-Sáez
mesh_terms: D002244:Carbon / Q000378:metabolism*; D002523:Edible Grain / Q000254:growth & development / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D014908:Triticum / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D002244:Carbon; D012273:Ribulose-Bisphosphate Carboxylase; D009584:Nitrogen
keywords: Carbon accumulation; Rubisco; ear; grain yield; nitrogen accumulation