Acclimation of Arabidopsis thaliana to the light environment: the existence of separate low light and high light responses.
The capacity for photosynthetic acclimation in Arabidopsis thaliana (L.) Heynh. cv. Landsberg erecta was assessed during growth over a broad range of irradiance. Discontinuities in the response to growth irradiance were revealed for the light- and CO2-saturated rate of photosynthesis (Pmax) and the ratio of chlorophyll a to chlorophyll b (Chl a/b). Three separate phases in the response of Pmax and Chl a/b to growth light were evident, with increases at low and high irradiance ranges and a plateau at intermediate irradiance. By measuring all chlorophyll-containing components of the thylakoid membrane that contribute to Chl a/b we reveal that distinct strategies for growth at low and high irradiance underlie the discontinuous response. These strategies include, in addition to changes in the major light-harvesting complexes of photosystem II (LHCII), large shifts in the amounts of both reaction centres as well as significant changes in the levels of minor LHCII and LHCI components.
Bailey
S
S
Robert Hill Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, UK. sbailey@cell.bio.warwick.ac.uk
Walters
R G
RG
Jansson
S
S
Horton
P
P
D000064:Acclimatization / Q000502:physiology* / Q000528:radiation effects; D017360:Arabidopsis / Q000502:physiology* / Q000528:radiation effects; D002245:Carbon Dioxide / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D008027:Light; D045342:Light-Harvesting Protein Complexes; D010101:Oxygen Consumption; D010788:Photosynthesis / Q000528:radiation effects; D045322:Photosynthetic Reaction Center Complex Proteins / Q000528:radiation effects; D045332:Photosystem II Protein Complex; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D002245:Carbon Dioxide; C037184:chlorophyll b; D012273:Ribulose-Bisphosphate Carboxylase; D000077194:Chlorophyll A