title: Release of resource constraints allows greater carbon allocation to secondary metabolites and storage in winter wheat.
abstract: The atmospheric CO2concentration ([CO2]) is rapidly increasing, and this may have substantial impact on how plants allocate metabolic resources. A thorough understanding of allocation priorities can be achieved by modifying [CO2] over a large gradient, including low [CO2], thereby altering plant carbon (C) availability. Such information is of critical importance for understanding plant responses to global environmental change. We quantified the percentage of daytime whole-plant net assimilation (A) allocated to night-time respiration (R), structural growth (SG), nonstructural carbohydrates (NSC) and secondary metabolites (SMs) during 8 weeks of vegetative growth in winter wheat (Triticum aestivum) growing at low, ambient and elevated [CO2] (170, 390 and 680 ppm). R/A remained relatively constant over a large gradient of [CO2]. However, with increasing C availability, the fraction of assimilation allocated to biomass (SG + NSC + SMs), in particular NSC and SMs, increased. At low [CO2], biomass and NSC increased in leaves but decreased in stems and roots, which may help plants achieve a functional equilibrium, that is, overcome the most severe resource limitation. These results reveal that increasing C availability from rising [CO2] releases allocation constraints, thereby allowing greater investment into long-term survival in the form of NSC and SMs.
authors.affiliation: Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany.
authors.forename: Jianbei
authors.identifier: http://orcid.org/0000-0001-5286-5645
authors.initials: J
authors.lastname: Huang
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany.|Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa.
authors.forename: Almuth
authors.initials: A
authors.lastname: Hammerbacher
authors.affiliation: Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany.
authors.forename: Lenka
authors.initials: L
authors.lastname: Forkelová
authors.affiliation: Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Hartmann
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D019069:Cell Respiration; D005740:Gases / Q000378:metabolism; D008954:Models, Biological; D018515:Plant Leaves; D012621:Seasons; D064210:Secondary Metabolism; D012995:Solubility; D000073893:Sugars / Q000378:metabolism; D014908:Triticum / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005740:Gases; D000073893:Sugars; D002244:Carbon
keywords: CO2; carbon allocation; growth; respiration; storage carbohydrates