Abstract
Previous studies of elevated carbon dioxide concentration ([CO2]) on crop canopies have found that radiation-use efficiency is increased more than radiation interception efficiency. It is assumed that increased radiation-use efficiency is due to changes in leaf-level physiology; however, canopy structure can affect radiation-use efficiency if leaves are displayed in a manner that optimizes their physiological capacity, even though the canopy intercepts the same amount of light. In order to determine the contributions of physiology and canopy structure to radiation-use and radiation-interception efficiency, this study relates leaf-level physiology and leaf display to photosynthetic rate of the outer canopy. We used a new imaging approach that delivers three-dimensional maps of the outer canopy during the growing season. The 3D data were used to model leaf orientation and mean photosynthetic electron transport of the outer canopy to show that leaf orientation changes did not contribute to increased radiation-use; i. e. leaves of the outer canopy showed similar diurnal leaf movements and leaf orientation in both treatments. Elevated [CO2] resulted in an increased maximum electron transport rate (ETRmax) of light reactions of photosynthesis. Modeling of canopy light interception showed that stimulated leaf-level electron transport at elevated [CO2], and not alterations in leaf orientation, was associated with stimulated radiation-use efficiency and biomass production in elevated [CO2]. This study provides proof of concept of methodology to quantify structure-function relationships in combination, allowing a quantitative estimate of the contribution of both effects to canopy energy conversion under elevated [CO2].
| Original language | English (US) |
|---|---|
| Pages (from-to) | 15-25 |
| Number of pages | 11 |
| Journal | Photosynthesis research |
| Volume | 105 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jun 24 2010 |
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Keywords
- Chlorophyll fluorescence
- Elevated CO
- Glycine max
- Light reactions
- Photosynthesis
- Structure-function relations
- Three-dimensional canopy surface
ASJC Scopus subject areas
- Biochemistry
- Plant Science
- Cell Biology
Cite this
Altered physiological function, not structure, drives increased radiation-use efficiency of soybean grown at elevated CO2. / Rascher, Uwe; Biskup, Bernhard; Leakey, Andrew; McGrath, Justin M.; Ainsworth, Elizabeth.
In: Photosynthesis research, Vol. 105, No. 1, 24.06.2010, p. 15-25.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Altered physiological function, not structure, drives increased radiation-use efficiency of soybean grown at elevated CO2
AU - Rascher, Uwe
AU - Biskup, Bernhard
AU - Leakey, Andrew
AU - McGrath, Justin M.
AU - Ainsworth, Elizabeth
PY - 2010/6/24
Y1 - 2010/6/24
N2 - Previous studies of elevated carbon dioxide concentration ([CO2]) on crop canopies have found that radiation-use efficiency is increased more than radiation interception efficiency. It is assumed that increased radiation-use efficiency is due to changes in leaf-level physiology; however, canopy structure can affect radiation-use efficiency if leaves are displayed in a manner that optimizes their physiological capacity, even though the canopy intercepts the same amount of light. In order to determine the contributions of physiology and canopy structure to radiation-use and radiation-interception efficiency, this study relates leaf-level physiology and leaf display to photosynthetic rate of the outer canopy. We used a new imaging approach that delivers three-dimensional maps of the outer canopy during the growing season. The 3D data were used to model leaf orientation and mean photosynthetic electron transport of the outer canopy to show that leaf orientation changes did not contribute to increased radiation-use; i. e. leaves of the outer canopy showed similar diurnal leaf movements and leaf orientation in both treatments. Elevated [CO2] resulted in an increased maximum electron transport rate (ETRmax) of light reactions of photosynthesis. Modeling of canopy light interception showed that stimulated leaf-level electron transport at elevated [CO2], and not alterations in leaf orientation, was associated with stimulated radiation-use efficiency and biomass production in elevated [CO2]. This study provides proof of concept of methodology to quantify structure-function relationships in combination, allowing a quantitative estimate of the contribution of both effects to canopy energy conversion under elevated [CO2].
AB - Previous studies of elevated carbon dioxide concentration ([CO2]) on crop canopies have found that radiation-use efficiency is increased more than radiation interception efficiency. It is assumed that increased radiation-use efficiency is due to changes in leaf-level physiology; however, canopy structure can affect radiation-use efficiency if leaves are displayed in a manner that optimizes their physiological capacity, even though the canopy intercepts the same amount of light. In order to determine the contributions of physiology and canopy structure to radiation-use and radiation-interception efficiency, this study relates leaf-level physiology and leaf display to photosynthetic rate of the outer canopy. We used a new imaging approach that delivers three-dimensional maps of the outer canopy during the growing season. The 3D data were used to model leaf orientation and mean photosynthetic electron transport of the outer canopy to show that leaf orientation changes did not contribute to increased radiation-use; i. e. leaves of the outer canopy showed similar diurnal leaf movements and leaf orientation in both treatments. Elevated [CO2] resulted in an increased maximum electron transport rate (ETRmax) of light reactions of photosynthesis. Modeling of canopy light interception showed that stimulated leaf-level electron transport at elevated [CO2], and not alterations in leaf orientation, was associated with stimulated radiation-use efficiency and biomass production in elevated [CO2]. This study provides proof of concept of methodology to quantify structure-function relationships in combination, allowing a quantitative estimate of the contribution of both effects to canopy energy conversion under elevated [CO2].
KW - Chlorophyll fluorescence
KW - Elevated CO
KW - Glycine max
KW - Light reactions
KW - Photosynthesis
KW - Structure-function relations
KW - Three-dimensional canopy surface
UR - http://www.scopus.com/inward/record.url?scp=77953696355&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953696355&partnerID=8YFLogxK
U2 - 10.1007/s11120-010-9548-6
DO - 10.1007/s11120-010-9548-6
M3 - Article
C2 - 20407832
AN - SCOPUS:77953696355
VL - 105
SP - 15
EP - 25
JO - Photosynthesis Research
JF - Photosynthesis Research
SN - 0166-8595
IS - 1
ER -