During photosynthetic state transitions, a fraction of the major light-harvesting complex (LHCII) shuttles between photosystems II (PSII) and I (PSI), depending on whether or not it is phosphorylated. Its phosphorylation state in turn depends on the relative activity of the two photosystems, which is a function of redox state and illumination parameters. In the psae1-1 mutant of Arabidopsis thaliana (L.) Heynh., amounts of the PSI subunits E, C, D, H and L are decreased. A fraction of LHCII is stably associated with PSI when plants are exposed to low light conditions, giving rise to a high-molecular-mass protein–pigment complex detectable in native protein gels. The formation of this abnormalLHC II–PSI complex is associated with an almost complete suppression of state transitions, a drastic increase in the levels of phosphorylated LHCII under all light regimes tested, and a permanent reduction in PSII antenna size. All these observations suggest that the altered polypeptide composition of PSI perturbs the docking of phosphorylated LHCII, making psae1-1 a unique mutant for the study of PSI–LHCII interactions and additionaleffect s of the mutation, such as a decrease in grana stacking and increased adenylate kinase activity.
A stable LHCII-PSI aggregate and suppression of photosynthetic state transitions in the psae1-1 mutant of Arabidopsis thaliana. / P. Pesaresi, C. Lunde, P. Jahns D. Tarantino, J. Meurer, C. Varotto, R.D. Hirtz, C. Soave, H.V. Scheller, F. Salamini, D. Leister. - In: PLANTA. - ISSN 0032-0935. - 215:6(2002 Aug 09), pp. 940-948.
|Titolo:||A stable LHCII-PSI aggregate and suppression of photosynthetic state transitions in the psae1-1 mutant of Arabidopsis thaliana.|
PESARESI, PAOLO (Primo)
|Parole Chiave:||Arabidopsis; Mutant; Photosynthesis; Photosystem I; State transition|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
Settore BIO/18 - Genetica
|Data di pubblicazione:||9-ago-2002|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s00425-002-0835-0|
|Appare nelle tipologie:||01 - Articolo su periodico|