Letter to Nature. Low-light-adapted Prochlorococcus species possess specific antennae for each photosystem

Bibby, T.S., Mary, I., Nield, J., Partensky, F. and Barber, J. (2003) Letter to Nature. Low-light-adapted Prochlorococcus species possess specific antennae for each photosystem. Nature, 424 (6952), 1051-1054. (doi:10.1038/nature01933).

Abstract

Prochlorococcus, the most abundant genus of photosynthetic organisms, owes its remarkably large depth distribution in the oceans to the occurrence of distinct genotypes adapted to either low- or high-light niches. The pcb genes, encoding the major chlorophyll-binding, light-harvesting antenna proteins in this genus, are present in multiple copies in low-light strains but as a single copy in high-light strains. The basis of this differentiation, however, has remained obscure. Here we show that the moderate low-light-adapted strain Prochlorococcus sp. MIT 9313 has one iron-stress-induced pcb gene encoding an antenna protein serving photosystem I (PSI)—comparable to isiA genes from cyanobacteria—and a constitutively expressed pcb gene encoding a photosystem II (PSII) antenna protein. By comparison, the very low-light-adapted strain SS120 has seven pcb genes encoding constitutive PSI and PSII antennae, plus one PSI iron-regulated pcb gene, whereas the high-light-adapted strain MED4 has only a constitutive PSII antenna. Thus, it seems that the adaptation of Prochlorococcus to low light environments has triggered a multiplication and specialization of Pcb proteins comparable to that found for Cab proteins in plants and green algae.

This record has no associated files available for download.

Contributors

Download statistics