Release of resource constraints allows greater carbon allocation to secondary metabolites and storage in winter wheat |
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| Authors: | Jianbei Huang Almuth Hammerbacher Lenka Forkelová Henrik Hartmann |
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| Affiliation: | 1. Max Planck Institute for Biogeochemistry, Jena, Germany;2. Max Planck Institute for Chemical Ecology, Jena, Germany;3. Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa |
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| Abstract: | The atmospheric CO2 concentration (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. |
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| Keywords: | carbon allocation CO2 growth respiration storage carbohydrates |
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