The oxidation of biological molecules by reactive oxygen species (ROS) can render them inactive or toxic. This includes the oxidation of RNA, which appears to underlie the detrimental effects of oxidative stress, aging and certain neurodegenerative diseases. Here, we investigate the management of oxidized RNA in the chloroplast of the green alga Chlamydomonas reinhardtii. Our immunofluorescence...

The maize nuclear gene crp1 is required for the translation of the chloroplast petA and petD mRNAs and for the processing of the petD mRNA from a polycistronic precursor. In order to understand the biochemical role of the crp1 gene product and the interconnections between chloroplast translation and RNA metabolism, the crp1 gene and cDNA were cloned. The predicted crp1 gene product (CRP1) is re...

BACKGROUND Eukaryotic cells arose through the uptake of bacterial endosymbionts and their gradual conversion into cell organelles (mitochondria and chloroplasts). In this process, a massive transfer of genes from the genome of the endosymbiont to the nuclear genome of the host cell occurred. Whereas intron-free organellar genes could conceivably enter the nucleus as DNA pieces and become functi...

Chloroplast sequence contamination in 16S ribosomal RNA gene (16S) analyses can be particularly problematic when sampling microbial communities in plants and folivorous arthropods. We previously encountered high levels of plastid contamination in herbivorous insect samples when we used the predominant 454 pyrosequencing 16S methodologies described in the literature. 799F, a primer previously fo...

Cucumis sativus L. seeds and 5-day-old dark-grown cotyledons contain 25 and 18 S cytoplasmic ribosomal RNAs as main components. The major increase in nucleic acid content in both green and etiolated cotyledons occurs between days 5 and 7 of germination. This increase is characterized by an important synthesis of 23 and 16 S plastid (chloroplast and proplastid) ribosomal RNAs. Proplastid RNA syn...

All positive-strand RNA viruses induce the biogenesis of cytoplasmic membrane-bound virus factories for viral genome multiplication. We have previously demonstrated that upon plant potyvirus infection, the potyviral 6K2 integral membrane protein induces the formation of ER-derived replication vesicles that subsequently target chloroplasts for robust genome replication. Here, we report that foll...

Arabidopsis thaliana chloroplasts contain at least two 3' to 5' exoribonucleases, polynucleotide phosphorylase (PNPase) and an RNase R homolog (RNR1). PNPase has been implicated in both mRNA and 23S rRNA 3' processing. However, the observed maturation defects do not affect chloroplast translation, suggesting that the overall role of PNPase in maturation of chloroplast rRNA is not essential. Her...

RNA editing alters plant mitochondrial and chloroplast transcripts by converting specific cytidines to uridines, which usually results in a change in the amino acid sequence of the translated protein. Systematic studies have experimentally identified sites of RNA editing in organellar transcriptomes from several species, but these analyses have not kept pace with rate of genome sequencing. The ...

Plant nuclear genomes encode hundreds of predicted organellar RNA binding proteins, few of which have been connected with their physiological RNA substrates and functions. In fact, among the largest family of putative RNA binding proteins in plants, the pentatricopeptide repeat (PPR) family, no physiologically relevant RNA ligands have been firmly established. We used the chloroplast-splicing f...

Viral infection of farmed fish and shellfish represents a major issue within the aquaculture industry. One potential control strategy involves RNA interference viral gene expression through oral delivery specific double-stranded (dsRNA). In previous work, we have shown that recombinant dsRNA can be produced in chloroplast edible microalga Chlamydomonas reinhardtii used to disease shrimp. Here, ...