The efficiency with which crop plants use their resources of light, water, and fertilizer nitrogen could be enhanced by replacing their CO(2)-fixing enzyme, d-ribulose-1,5-bisphosphate carboxylase-oxygenase (RubisCO), with more efficient forms, such as those found in some algae, for example. This important challenge has been frustrated by failure of all previous attempts to substitute a fully f...

Dual-conditional positive/negative selection markers are versatile genetic tools for manipulating genomes. Plastid genomes are relatively small and conserved DNA molecules that can be manipulated precisely by homologous recombination. High-yield expression of recombinant products and maternal inheritance of plastid-encoded traits make plastids attractive sites for modification. Here, we describ...

Plastid genomes of higher plants contain a conserved set of ribosomal protein genes. Although plastid translational activity is essential for cell survival in tobacco (Nicotiana tabacum), individual plastid ribosomal proteins can be nonessential. Candidates for nonessential plastid ribosomal proteins are ribosomal proteins identified as nonessential in bacteria and those whose genes were lost f...

The transcriptional machineries of plastids and mitochondria in higher plants exhibit striking similarities. All mitochondrial genes and part of the plastid genes are transcribed by related phage-type RNA polymerases. Furthermore, the majority of mitochondrial promoters and a subset of plastid promoters show a similar structural organization. We show here that the plant mitochondrial atpA promo...

Chromatin immunoprecipitation (ChIP) has been used to detect binding of DNA-binding proteins to sites in nuclear and mitochondrial genomes. Here, we describe a method for detecting protein-binding sites on chloroplast DNA, using modifications to the nuclear ChIP procedures. The method was developed using the lac operator (lacO)/lac repressor (LacI) system from Escherichia coli. The lacO sequenc...

Plastid transformation for the expression of recombinant proteins and entire metabolic pathways has become a promising tool for plant biotechnology. However, large-scale application of this technology has been hindered by some technical bottlenecks, including lack of routine transformation protocols for agronomically important crop plants like rice or maize. Currently, there are no standard or ...

Mitochondria and chloroplasts (photosynthetic members of the plastid family of cytoplasmic organelles) in eukaryotic cells originated more than a billion years ago when an ancestor of the nucleated cell engulfed two different prokaryotes in separate sequential events. Extant cytoplasmic organellar genomes contain very few genes compared with their candidate free-living ancestors, as most have f...

Hemophilia A is the X-linked bleeding disorder caused by deficiency of coagulation factor VIII (FVIII). To address serious complications of inhibitory antibody formation in current replacement therapy, we created tobacco transplastomic lines expressing FVIII antigens, heavy chain (HC) and C2, fused with the transmucosal carrier, cholera toxin B subunit. Cholera toxin B-HC and cholera toxin B-C2...

Facile methods of genetic transformation are of outstanding importance for both basic and applied research. For many years, transgenic technologies for plants were restricted to manipulations of the nuclear genome. More recently, a second genome of the plant cell has become amenable to genetic engineering: the prokaryotically organized circular genome of the chloroplast. The possibility to dire...