Changes in leaf optical properties associated with light‐dependent chloroplast movements

• Published in: Plant, cell and environment Vol. 34; no. 12; pp. 2047 - 2059
• Main Authors: DAVIS, PHILLIP A, CAYLOR, STEVEN, WHIPPO, CRAIG W, HANGARTER, ROGER P
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-12-2011; Blackwell
• Subjects: absorptance; Absorption; Anatomy; Biological and medical sciences; Chlorophyll; Chlorophyll - metabolism; chloroplast movement; chloroplasts; Chloroplasts - physiology; Fundamental and applied biological sciences. Psychology; leaf absorption; leaf anatomy; leaf reflectance; leaf transmittance; leaves; Light; light acclimation; light intensity; light scattering; Optical Phenomena; optical properties; Packaging; Photosynthesis; Plant Leaves - anatomy & histology; plants; sieves; sun; Light effect; Light scattering; Plant ecology; Plant leaf; leaf transmittance; Anatomy; Transmittance; leaf absorption; light acclimation; leaf anatomy; Absorption; chloroplast movement; Light; Optical properties; leaf reflectance; Chloroplast; Adaptation; Reflectance
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.1365-3040.2011.02402.x

We surveyed 24 plant species to examine how leaf anatomy influenced chloroplast movement and how the optical properties of leaves change with chloroplast position. All species examined exhibited light‐dependent chloroplast movements but the associated changes in leaf absorptance varied considerably in magnitude. Chloroplast movement‐dependent changes in leaf absorptance were greatest in shade species, in which absorptance changes of >10% were observed between high‐ and low‐light treatments. Using the Kubelka–Munk theory, we found that changes in the absorption (k) and chlorophyll a absorption efficiency (k*) associated with chloroplast movement correlated with cell diameter, such that the narrower, more columnar cells found in sun leaves restricted the ability of chloroplasts to move. The broader, more spherical cells of shade leaves allowed greater chloroplast rearrangements and in low‐light conditions allowed efficient light capture. Across the species tested, light‐dependent chloroplast movements modulated leaf optical properties and light absorption efficiency by manipulating the package (sieve or flattening) effect but not the detour (path lengthening) effect.