TY  - JOUR
AU  - Pieruschka, R.
AU  - Chavarria-Krauser, A.
AU  - Schurr, U.
AU  - Jahnke, S.
TI  - Photosynthesis in lightfleck areas of homobaric and heterobaric leaves
JO  - The journal of experimental botany
VL  - 61
IS  - 4
SN  - 0022-0957
CY  - Oxford
PB  - Univ. Press
M1  - PreJuSER-9362
SP  - 1031 - 1039
PY  - 2010
N1  - We are indebted to Dr Shizue Matsubara for critical reading of the manuscript. This work was part of the doctoral thesis of RP at Mathematisch-Naturwissenschaftliche Fakultat, Heinrich-Heine Universitat, Dusseldorf, Germany.
AB  - Leaves within a canopy are exposed to a spatially and temporally fluctuating light environment which may cause lateral gradients in leaf internal CO(2) concentration and diffusion between shaded and illuminated areas. In previous studies it was hypothesized that lateral CO(2) diffusion may support leaf photosynthesis, but the magnitude of this effect is still not well understood. In the present study homobaric leaves of Vicia faba or heterobaric leaves of Glycine max were illuminated with lightflecks of different sizes, mimicking sunflecks. Photosynthetic properties of the lightfleck areas were assessed with combined gas exchange measurements and chlorophyll fluorescence imaging. Lateral diffusion in homobaric leaves with an interconnected intercellular air space stimulated photosynthesis and the effect was largest in small lightfleck areas, in particular when plants were under drought stress. Such effects were not observed in the heterobaric leaves with strongly compartmented intercellular gas spaces. It is concluded that lateral diffusion may significantly contribute to photosynthesis of lightfleck areas of homobaric leaves depending on lightfleck size, lateral diffusivity, and stomatal conductance. Since homobaric leaf structures have been reported for many plant species, it is hypothesized that leaf homobary may have an impact on overall plant performance under conditions with a highly heterogeneous light environment.
KW  - Carbon Dioxide: chemistry
KW  - Carbon Dioxide: metabolism
KW  - Diffusion
KW  - Kinetics
KW  - Light
KW  - Photosynthesis: radiation effects
KW  - Plant Leaves: anatomy & histology
KW  - Plant Leaves: chemistry
KW  - Plant Leaves: metabolism
KW  - Plant Leaves: radiation effects
KW  - Soybeans: anatomy & histology
KW  - Soybeans: chemistry
KW  - Soybeans: metabolism
KW  - Soybeans: radiation effects
KW  - Vicia faba: anatomy & histology
KW  - Vicia faba: chemistry
KW  - Vicia faba: metabolism
KW  - Vicia faba: radiation effects
KW  - Carbon Dioxide (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:20008895
C2  - pmc:PMC2826648
UR  - <Go to ISI:>//WOS:000275567300009
DO  - DOI:10.1093/jxb/erp368
UR  - https://juser.fz-juelich.de/record/9362
ER  -