Do epidermal lens cells facilitate the absorptance of diffuse light?
- 1 July 2007
- journal article
- Published by Wiley in American Journal of Botany
- Vol. 94 (7), 1061-1066
- https://doi.org/10.3732/ajb.94.7.1061
Abstract
Many understory plants rely on diffuse light for photosynthesis because direct light is usually scattered by upper canopy layers before it strikes the forest floor. There is a considerable gap in the literature concerning the interaction of direct and diffuse light with leaves. Some understory plants have well-developed lens-shaped epidermal cells, which have long been thought to increase the absorption of diffuse light. To assess the role of epidermal cell shape in capturing direct vs. diffuse light, we measured leaf reflectance and transmittance with an integrating sphere system using leaves with flat (Begonia erythrophylla, Citrus reticulata, and Ficus benjamina) and lens-shaped epidermal cells (B. bowerae, Colocasia esculenta, and Impatiens velvetea). In all species examined, more light was absorbed when leaves were irradiated with direct as opposed to diffuse light. When leaves were irradiated with diffuse light, more light was transmitted and more was reflected in both leaf types, resulting in absorptance values 2–3% lower than in leaves irradiated with direct light. These data suggest that lens-shaped epidermal cells do not aid the capture of diffuse light. Palisade and mesophyll cell anatomy and leaf thickness appear to have more influence in the capture and absorption of light than does epidermal cell shape.Keywords
Funding Information
- National Science Foundation (DBI 0454933)
This publication has 24 references indexed in Scilit:
- The Light Environment and Cellular Optics of the Snow Alga Chlamydomonas nivalis (Bauer) Wille†¶Photochemistry and Photobiology, 2007
- Pinatubo, Diffuse Light, and the Carbon CycleScience, 2003
- Response of a Deciduous Forest to the Mount Pinatubo Eruption: Enhanced PhotosynthesisScience, 2003
- On the direct effect of clouds and atmospheric particles on the productivity and structure of vegetationOecologia, 2001
- Focusing of light by leaf epidermal cellsPhysiologia Plantarum, 1996
- Penumbral Effects on Sunlight Penetration in Plant CommunitiesEcology, 1989
- Epidermal cells functioning as lenses in leaves of tropical rain-forest shade plantsApplied Optics, 1985
- Optical Parameters of Leaves of 30 Plant SpeciesPlant Physiology, 1973
- Light Intensity and Sunfleck‐size Distributions in Plant Canopies1Agronomy Journal, 1971
- Reflectance and Transmittance of Light by LeavesPlant Physiology, 1971