The role of environment, sink capacity, and carbon translocation in determining C3 plant responses to elevated [CO2]
type: CreativeWork
description: Over the past century, CO2 concentration ([CO2]) in the atmosphere has been steadily increasing, leading to global climate change. Elevated [CO2] increases yield, biomass, and photosynthesis in most C3 plants, but the degree to which elevated [CO2] stimulates crop yields can depend upon climatic factors and plant physiological attributes, including sink strength and sugar transport capacity. This thesis uses field, laboratory, and meta-analytic techniques to investigate factors that influence the responsiveness of plants to elevated [CO2], with the ultimate aim of understanding variation in and improving future crop production. Photosynthesis is typically stimulated in C3 crops exposed to elevated [CO2], while stomatal conductance is typically decreased. Theory predicts that the magnitude of stimulation of photosynthesis at elevated [CO2] is greater at higher temperatures. In Chapter 2, the degree to which these physiological responses of C3 crops to elevated [CO2] would translate to yield responses was tested. Using a global dataset of published yield data from Free Air CO2 Enrichment (FACE) and Open Top Chamber (OTC) experiments, there was greater yield response to elevated [CO2] in C3 crops under dryer conditions, but there was no correlation between yield response to elevated [CO2] and growing season temperature. Thus, the theoretical response of photosynthesis to elevated [CO2] and temperature was not observed in seed yield, perhaps due to direct effects of temperature on respiration or reproductive processes. In Chapter 3, intraspecific variation in soybean (Glycine max) response to elevated [CO2] and the agronomic traits associated with greater yield responsiveness to elevated [CO2] were analyzed. Eighteen soybean cultivars, varying in maturity group, year of release date, and agronomic traits, were grown at SoyFACE from 2003 to 2008. There was significant intraspecific variation in yield response to elevated [CO2], with shorter cultivars and those with high …
abstract: Over the past century, CO2 concentration ([CO2]) in the atmosphere has been steadily increasing, leading to global climate change. Elevated [CO2] increases yield, biomass, and photosynthesis in most C3 plants, but the degree to which elevated [CO2] stimulates crop yields can depend upon climatic factors and plant physiological attributes, including sink strength and sugar transport capacity. This thesis uses field, laboratory, and meta-analytic techniques to investigate factors that influence the responsiveness of plants to elevated [CO2], with the ultimate aim of understanding variation in and improving future crop production. Photosynthesis is typically stimulated in C3 crops exposed to elevated [CO2], while stomatal conductance is typically decreased. Theory predicts that the magnitude of stimulation of photosynthesis at elevated [CO2] is greater at higher temperatures. In Chapter 2, the degree to which these physiological responses of C3 crops to elevated [CO2] would translate to yield responses was tested. Using a global dataset of published yield data from Free Air CO2 Enrichment (FACE) and Open Top Chamber (OTC) experiments, there was greater yield response to elevated [CO2] in C3 crops under dryer conditions, but there was no correlation between yield response to elevated [CO2] and growing season temperature. Thus, the theoretical response of photosynthesis to elevated [CO2] and temperature was not observed in seed yield, perhaps due to direct effects of temperature on respiration or reproductive processes. In Chapter 3, intraspecific variation in soybean (Glycine max) response to elevated [CO2] and the agronomic traits associated with greater yield responsiveness to elevated [CO2] were analyzed. Eighteen soybean cultivars, varying in maturity group, year of release date, and agronomic traits, were grown at SoyFACE from 2003 to 2008. There was significant intraspecific variation in yield response to elevated [CO2], with shorter cultivars and those with high …
author: Bishop, Kristen A
language: en
keywords: Climate change, food security, crop yield, phloem
date published: 2016-07-07T20:27:19Z
date modified: 2026-07-22T22:26:34Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/90755