During photosynthesis, energy from solar radiation is used to convert atmospheric carbon dioxide into intermediates that are used within and outside the chloroplast for a multitude of metabolic pathways. The daily fixed carbon is exported from the chloroplasts as triose phosphates and 3-phosphoglycerate. In contrast, nongreen plastids rely on the import of carbon, mainly hexose phosphates. Most...

Secondary plastids are acquired by the engulfment and retention of eukaryotic algae, which results in an additional surrounding membrane or pair of membranes relative to the more familiar primary plastids of land plants. In most cases, the endocytosed alga loses its eukaryotic genome as it becomes integrated, but in two algal groups, the cryptophytes and chlorarachniophytes, the secondary plast...

Cryptomonad algae acquired their plastids by the secondary endosymbiotic uptake of a eukaryotic red alga. Several other algal lineages acquired plastids through such an event [1], but cryptomonads are distinguished by the retention of a relic red algal nucleus, the nucleomorph [2]. The nucleomorph (and its absence in other lineages) can reveal a great deal about the process and history of endos...

Plastids are plant cell organelles with many essential functions in plant metabolism. Among these are photosynthesis, amino acid and fatty acid biosynthesis, as well as the synthesis of several secondary metabolites. All plastids originate from undifferentiated proplastids, which are restricted to meristematic tissues and undifferentiated cells. Depending on the tissue, proplastids can develop ...

Plastids are plant cell organelles with many essential functions in plant metabolism. Among these are photosynthesis, amino acid and fatty acid biosynthesis, as well as the synthesis of several secondary metabolites. All plastids originate from undifferentiated proplastids, which are restricted to meristematic tissues and undifferentiated cells. Depending on the tissue, proplastids can develop ...

The plastids of chlorarachniophytes were derived from an ancestral green alga via secondary endosymbiosis. Thus, genes from the "green" lineage via secondary endosymbiotic gene transfer (EGT) are expected in the nuclear genomes of the Chlorarachniophyta. However, several recent studies have revealed the presence of "red" genes in their nuclear genomes. To elucidate the origin of such "red" gene...

Dinoflagellates harboring diatom endosymbionts (termed "dinotoms") have undergone a process often referred to as "tertiary endosymbiosis"--the uptake of algae containing secondary plastids and integration of those plastids into the new host. In contrast to other tertiary plastids, and most secondary plastids, the endosymbiont of dinotoms is distinctly less reduced, retaining a number of cellula...

Retrograde signalling from the plastid to the nucleus, also known as plastid signalling, plays a key role in coordinating nuclear gene expression with the functional state of plastids. Inhibitors that cause plastid dysfunction have been suggested to generate specific plastid signals related to their modes of action. However, the molecules involved in plastid signalling remain to be identified. ...

The chlorophyll c-containing algae comprise four major lineages: dinoflagellates, haptophytes, heterokonts, and cryptophytes. These four lineages have sometimes been grouped together based on their pigmentation, but cytological and rRNA data had suggested that they were not a monophyletic lineage. Some molecular data support monophyly of the plastids, while other plastid and host data suggest d...