Illuminating the diversity of carotenoids in microalgal eyespots and phototaxis.
Plant Signal Behav
; 18(1): 2257348, 2023 12 31.
Article
en En
| MEDLINE
| ID: mdl-37724547
ABSTRACT
Photosynthetic organisms biosynthesize various carotenoids, a group of light-absorbing isoprenoid pigments that have key functions in photosynthesis, photoprotection, and phototaxis. Microalgae, in particular, contain diverse carotenoids and carotenoid biosynthetic pathways as a consequence of the various endosymbiotic events in their evolutionary history. Carotenoids such as astaxanthin, diadinoxanthin, and fucoxanthin are unique to algae. In microalgae, carotenoids are concentrated in the eyespot, a pigmented organelle that is important for phototaxis. A wide range of microalgae, including chlorophytes, euglenophytes, ochrophytes, and haptophytes, have an eyespot. In the chlorophyte Chlamydomonas reinhardtii, carotenoid layers in the eyespot reflect light to amplify the photosignal and shield photoreceptors from light, thereby enabling precise phototaxis. Our recent research revealed that, in contrast to the ß-carotene-rich eyespot of C. reinhardtii, the euglenophyte Euglena gracilis relies on zeaxanthin for stable eyespot formation and phototaxis. In this review, we highlight recent advancements in the study of eyespot carotenoids and phototaxis in these microalgae, placing special emphasis on the diversity of carotenoid-dependent visual systems among microalgae.
Palabras clave
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Carotenoides
/
Microalgas
Idioma:
En
Revista:
Plant Signal Behav
Asunto de la revista:
BOTANICA
/
FISIOLOGIA
Año:
2023
Tipo del documento:
Article