Chlorophyll b-Containing Oxygenic Photosynthetic Prokaryotes: Oxychlorobacteria (Prochlorophytes)

• Published in: The Botanical review Vol. 72; no. 4; pp. 330 - 366
• Main Author: Griffiths, Dilwyn J
• Format: Journal Article
• Language: English
• Published: Bronx The New York Botanical Garden 01-10-2006; New York Botanical Garden; Springer Nature B.V
• Subjects: Algae; Animal morphology; Bacteria; Botany; chemical constituents of plants; Chlorophyll; Chlorophylls; Chloroplasts; Cyanobacteria; descriptions; DNA fingerprinting; Evolution; Genera; genetic relationships; genetic variation; literature reviews; molecular sequence data; Morphology (Animals); nucleotide sequences; Photosynthesis; Pigments; plant anatomy; Plant ecology; plant pigments; plant taxonomy; Plants; Prochlorococcus; Prochloron; Prochlorophyta; Prochlorophytes; Prochlorothrix; Prokaryotes; prokaryotic cells; quantitative analysis; Taxonomy; Thylakoids; ultrastructure; Australia
• ISSN: 0006-8101; 1874-9372
• DOI: 10.1663/0006-8101(2006)72[330:CBOPPO]2.0.CO;2

The major ultrastructural and pigment characteristics of three chlorophyll b-containing photosynthetic prokaryote genera, Prochloron, Prochlorothrix, and Prochlorococcus, are summarized. Aspects of their ecology are reviewed, as are also the major findings of comparisons among the three genera, and between them and the cyanobacteria, based on analyses of nucleotide sequences. The information summarized is discussed to assess how closely the three genera are related and whether they form a natural taxonomic grouping within the cyanobacteria. It is concluded that, although much of the evidence points to substantial differences among the three genera, the convenience of keeping them together as a group, namely, Oxychlorobacteria (formerly Prochlorophyta), outweighs certain inconsistencies revealed by analysis of a range of objective criteria. Current views on the possible significance of the group to considerations of the evolution of green chloroplasts are also presented.