Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
2 FORMS OF THE PHOTOSYSTEM-II D1 PROTEIN ALTER ENERGY-DISSIPATION ANDSTATE TRANSITIONS IN THE CYANOBACTERIUM SYNECHOCOCCUS SP PCC-7942
Autore:
CAMPBELL D; BRUCE D; CARPENTER C; GUSTAFSSON P; OQUIST G;
Indirizzi:
UMEA UNIV,DEPT PLANT PHYSIOL S-90187 UMEA SWEDEN BROCK UNIV,DEPT BIOL SCI ST CATHARINES ON L2S 3A1 CANADA
Titolo Testata:
Photosynthesis research
fascicolo: 2, volume: 47, anno: 1996,
pagine: 131 - 144
SICI:
0166-8595(1996)47:2<131:2FOTPD>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
RESPIRATORY ELECTRON FLOW; CHLOROPHYLL FLUORESCENCE; ANACYSTIS-NIDULANS; EXCITATION-ENERGY; NITROGEN ASSIMILATION; DISTINCT FORMS; LIGHT; PHOTOSYNTHESIS; PHOTOINHIBITION; ADAPTATION;
Keywords:
CHLOROPHYLL FLUORESCENCE; ELECTRON TRANSPORT; LIGHT-ACCLIMATION; LIGHT-HARVESTING; PHOTOSYNTHESIS; QUENCHING ANALYSIS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
56
Recensione:
Indirizzi per estratti:
Citazione:
D. Campbell et al., "2 FORMS OF THE PHOTOSYSTEM-II D1 PROTEIN ALTER ENERGY-DISSIPATION ANDSTATE TRANSITIONS IN THE CYANOBACTERIUM SYNECHOCOCCUS SP PCC-7942", Photosynthesis research, 47(2), 1996, pp. 131-144

Abstract

Synechococcus sp. PCC 7942 (Anacystis nidulans R2) contains two formsof the Photosystem II reaction centre protein D1, which differ in 25 of 360 amino acids. D1:1 predominates under low light hut is transiently replaced by D1:2 upon shifts to higher light. Mutant cells containing only D1:1 have lower photochemical energy capture efficiency and decreased resistance to photoinhibition, compared to cells containing D1:2. We show that when dark-adapted or under low to moderate light, cells with D1:1 have higher non-photochemical quenching of PS II fluorescence (higher q(N)) than do cells with D1:2. This is reflected in the 77 K chlorophyll emission spectra, with lower Photosystem II fluorescence at 697-698 nm in cells containing D1:1 than in cells with D1:2. This difference in quenching of Photosystem II fluorescence occurs upon excitation of both chlorophyll at 435 nm and phycobilisomes at 570 nm. Measurement of time-resolved room temperature fluorescence shows that Photosystem II fluorescence related to charge stabilization is quenched more rapidly in cells containing D1:1 than in those with D1:2. Cellscontaining D1:1 appear generally shifted towards State II, with PS IIdown-regulated, while cells with D1:2 tend towards State I. In these cyanobacteria electron transport away from PS II remains non-saturatedeven under photoinhibitory levels of light. Therefore, the higher activity of D1:2 Photosystem II centres may allow more rapid photochemical dissipation of excess energy into the electron transport chain. D1:1confers capacity for extreme State II which may be of benefit under low and variable light.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 18:59:09