Importance of Fluctuations in Light on Plant Photosynthetic Acclimation.
The acclimation of plants to light has been studied extensively, yet little is known about the effect of dynamic fluctuations in light on plant phenotype and acclimatory responses. We mimicked natural fluctuations in light over a diurnal period to examine the effect on the photosynthetic processes and growth of Arabidopsis (Arabidopsis thaliana). High and low light intensities, delivered via a realistic dynamic fluctuating or square wave pattern, were used to grow and assess plants. Plants subjected to square wave light had thicker leaves and greater photosynthetic capacity compared with fluctuating light-grown plants. This, together with elevated levels of proteins associated with electron transport, indicates greater investment in leaf structural components and photosynthetic processes. In contrast, plants grown under fluctuating light had thinner leaves, lower leaf light absorption, but maintained similar photosynthetic rates per unit leaf area to square wave-grown plants. Despite high light use efficiency, plants grown under fluctuating light had a slow growth rate early in development, likely due to the fact that plants grown under fluctuating conditions were not able to fully utilize the light energy absorbed for carbon fixation. Diurnal leaf-level measurements revealed a negative feedback control of photosynthesis, resulting in a decrease in total diurnal carbon assimilated of at least 20%. These findings highlight that growing plants under square wave growth conditions ultimately fails to predict plant performance under realistic light regimes and stress the importance of considering fluctuations in incident light in future experiments that aim to infer plant productivity under natural conditions in the field.
School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
Silvere
0000-0002-2105-2825
S
Vialet-Chabrand
School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
Jack S A
0000-0002-7282-8929
JS
Matthews
School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
Andrew J
0000-0001-5056-1306
AJ
Simkin
School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
Christine A
0000-0001-7997-7823
CA
Raines
School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom tlawson@essex.ac.uk.
Tracy
0000-0002-4073-7221
T
Lawson
D000064:Acclimatization / Q000502:physiology / Q000528:radiation effects*; D000465:Algorithms; D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000378:metabolism; D018533:Biomass; D015153:Blotting, Western; D002244:Carbon / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology; D004579:Electron Transport / Q000528:radiation effects; D008027:Light; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology / Q000528:radiation effects*; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors
D029681:Arabidopsis Proteins; D002734:Chlorophyll; D002244:Carbon