In this review, we consider a selection of recent advances in chloroplast biology. These include new findings concerning chloroplast evolution, such as the identification of Chlamydiae as a third partner in primary endosymbiosis, a second instance of primary endosymbiosis represented by the chromatophores found in amoebae of the genus Paulinella, and a new explanation for the longevity of captured chloroplasts (kleptoplasts) in sacoglossan sea slugs. The controversy surrounding the three-dimensional structure of grana, its recent resolution by tomographic analyses, and the role of the CURVATURE THYLAKOID1 (CURT1) proteins in supporting grana formation are also discussed. We also present an updated inventory of photosynthetic proteins and the factors involved in the assembly of thylakoid multiprotein complexes, and evaluate findings that reveal that cyclic electron flow involves NADPH dehydrogenase (NDH)- and PGRL1/PGR5-dependent pathways, both of which receive electrons from ferredoxin. Other topics covered in this review include new protein components of nucleoids, an updated inventory of the chloroplast proteome, new enzymes in chlorophyll biosynthesis and new candidate messengers in retrograde signaling. Finally, we discuss the first successful synthetic biology approaches that resulted in chloroplasts in which electrons from the photosynthetic light reactions are fed to enzymes derived from secondary metabolism.
Chloroplast evolution, structure and functions
Published 2014 in F1000Prime Reports
ABSTRACT
PUBLICATION RECORD
- Publication year
2014
- Venue
F1000Prime Reports
- Publication date
2014-06-02
- Fields of study
Biology, Medicine, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- chlamydiae
A bacterial lineage discussed as an additional partner in the origin scenario for primary plastids.
- cyclic electron flow
A photosynthetic electron-transport route that cycles electrons around photosystem I.
Aliases: CEF
- ferredoxin
An iron-sulfur electron carrier involved in photosynthetic electron transfer.
Aliases: Fd
- grana
Stacks of thylakoid membranes within chloroplasts.
- ndh- and pgrl1/pgr5-dependent pathways
Two ferredoxin-linked routes discussed together as components of cyclic electron flow.
Aliases: NDH and PGRL1/PGR5 pathways
- paulinella chromatophores
Photosynthetic organelles found in amoebae of the genus Paulinella.
Aliases: chromatophores
- primary endosymbiosis
An evolutionary process in which a host cell acquires a symbiont that becomes an organelle ancestor.