Abstract
The distance between veins has the potential to affect photosynthesis in C4 grasses because photon capture and photosynthetic carbon reduction are primarily restricted to vascular bundle sheath cells (BSC). For example, BSC density should increase as interveinal distance (IVD) decreases, and thus IVD may influence photon capture and photosynthesis in C4 grasses. The objective of this study is to evaluate the potential importance of IVD to the function of C4 grasses, and a literature survey is conducted to test the hypothesis that quantum yield of photosynthesis (Φ) increases with decreasing IVD. First, a meta-analysis of Φ and IVD values obtained for 12 C4 grass species supports this hypothesis as Φ and IVD are significantly negatively correlated (r=-0.61). Second, a regression of carbon isotope discrimination (Δ) versus IVD was conducted and the regression equation was used in a simple biochemical model that relates Φ to Δ and leakage of CO2 from the BSC. The modeling analysis also supports the hypothesis that Φ decreases with increasing IVD in C 4 grasses. C4 grasses are virtually absent from shaded habitats, and the biochemical model is employed to examine the implications of IVD for shade-tolerance in C4 grasses. The model predicts that only those species with uncommonly small IVD values are able to tolerate prolonged shade.
Original language | English (US) |
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Pages (from-to) | 532-542 |
Number of pages | 11 |
Journal | Oecologia |
Volume | 136 |
Issue number | 4 |
DOIs | |
State | Published - Aug 2003 |
Externally published | Yes |
Keywords
- C photosynthesis
- CO leakiness
- Carbon isotope
- Grasses
- Shade tolerance
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics