Limitations to photosynthesis by proton motive force-induced photosystem II photodamage.
Elife
; 52016 10 04.
Article
em En
| MEDLINE
| ID: mdl-27697149
ABSTRACT
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
/
Arabidopsis
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Força Próton-Motriz
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Tilacoides
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Complexo de Proteína do Fotossistema II
Idioma:
En
Revista:
Elife
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos