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. |
Autori: | 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 |
Rivista: | |
URL: | http://www.springerlink.com/content/w0p2pu0m5e22akgt/fulltext.pdf |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1007/s00425-002-0835-0 |
Appare nelle tipologie: | 01 - Articolo su periodico |