Time-resolved spectroscopic fluorescence imaging, transient absorption and vibrational spectroscopy of intact and photo-inhibited photosynthetic tissue.
Luminescence
; 20(3): 143-51, 2005.
Article
en En
| MEDLINE
| ID: mdl-15924324
Fluorescence, absorption and vibrational spectroscopic techniques were used to study spinach at the photosystem II (PS II), chloroplast and cellular levels and to determine the effects and mechanisms of ultraviolet-B (UV-B) photoinhibition of these structures. Two-photon fluorescence spectroscopic imaging of intact chloroplasts shows significant spatial variations in the component fluorescence spectra in the range 640-740 nm, indicating that the type and distribution of chlorophylls vary markedly with position in the chloroplast. The chlorophyll distributions and excitonic behaviour in chloroplasts and whole plant tissue were studied using picosecond time-gated fluorescence imaging, which also showed UV-induced kinetic changes that clearly indicate that UV-B induces both structural and excitonic uncoupling of chlorophylls within the light-harvesting complexes. Transient absorption measurements and low-frequency infrared and Raman spectroscopy show that the predominant sites of UV-B damage in PS II are at the oxygen-evolving centre (OEC) itself, as well as at specific locations near the OEC-binding sites.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Análisis Espectral
/
Cloroplastos
/
Complejo de Proteína del Fotosistema II
Idioma:
En
Revista:
Luminescence
Asunto de la revista:
BIOFISICA
/
BIOQUIMICA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Australia
Pais de publicación:
Reino Unido