Do changes in light direction affect absorption profiles in leaves?
Craig R. Brodersen A C, Thomas C. Vogelmann B A Department of Viticulture and Enology, One Shields Avenue, University of California, Davis, CA 95616, USA. B Department of Plant Biology, 109 Carrigan Drive, University of Vermont, Burlington, VT 05405, USA. C Corresponding author. Email: brodersen@ucdavis.edu Abstract Leaf anatomy plays a functional role in propagating light through the leaf; palisade mesophyll has been shown to facilitate the channelling of collimated light deeper into the spongy mesophyll. Direct measurements of the propagation of diffuse light into the leaf, however, are absent. Using chlorophyll fluorescence imaging of leaf cross-sections, we measured light absorption profiles in leaves under direct (collimated), diffuse and low-angle monochromatic light. Low-angle and diffuse light was absorbed closer to the irradiated surface than direct light perpendicular to the surface. The shapes of internal absorption profiles indicated that leaves were influenced by the direc
