The photon menace: kleptoplast protection in the photosynthetic sea slug Elysia timida.
J Exp Biol
; 222(Pt 12)2019 06 27.
Article
em En
| MEDLINE
| ID: mdl-31171599
ABSTRACT
Absorption of excessive light by photosymbiotic organisms leads to the production of reactive oxygen species that can damage both symbiont and host. This is highly relevant in sacoglossan sea slugs that host functional chloroplasts 'stolen' from their algal foods (kleptoplasts), because of limited repair capacities resulting from the absence of algal nuclear genes. Here, we experimentally demonstrate (i) a host-mediated photoprotection mechanism in the photosynthetic sea slug Elysia timida, characterized by the closure of the parapodia under high irradiance and the reduction of kleptoplast light exposure; and (ii) the activation of a reversible xanthophyll cycle in kleptoplasts, which allows excessive energy to be dissipated. The described mechanisms reduce photoinactivation under high irradiance. We conclude that both host-mediated behavioural and plastid-based physiological photoprotective mechanisms can mitigate oxidative stress induced by high light in E. timida These mechanisms may play an important role in the establishment of long-term photosynthetically active kleptoplasts.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
/
Cloroplastos
/
Gastrópodes
Limite:
Animals
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article