M. Reith, MOLECULAR-BIOLOGY OF RHODOPHYTE AND CHROMOPHYTE PLASTIDS, Annual review of plant physiology and plant molecular biology, 46, 1995, pp. 549-575
Recent information on the plastid genes and genomes of rhodophyte (red
algae) and chromophyte (yellow and brown algae) plastids are summariz
ed. The plastid genomes of these algae contain many more genes than th
ose of metaphyte (land plant) plastids, and the encoded proteins are i
nvolved in a much wider range of metabolic activities. Rhodophyte and
chromophyte plastid genomes contain very few introns and maintain many
ancestral gene operons, which suggests that they are more primitive t
han those of metaphytes. Hypotheses of plastid evolution (monophyletic
or polyphyletic primary origins) are discussed and assessed. The data
available at present support the idea that all plastids arose from a
single endosymbiotic event that involved a cyanobacterium and a eukary
ote host (monophyletic origin). Information from rhodophyte and chromo
phyte plastid genomes also provides insights into the evolution of oth
er organisms. Finally, the implications for plastid metabolism that ar
ise from the presence of several genes on rhodophyte and chromophyte p
lastid genomes are discussed.