Reverse genetic analysis of plastome genes
Most ORFs encoded by the plastome DNA belong to two
major classes: genes required for the maintenance and
expression of the organelle’s own genetic system (encodingrRNAs, tRNAs, ribosomal proteins, RNA polymerase
subunits) and photosynthesis-related genes. The functions
of relatively few hypothetical plastid ORFs (ycfs) are not
precisely known. Efficient homologous recombination in
chloroplasts allows wild-type ycf genes to be replaced by
knockout alleles, and their phenotypes studied in homotransplastomic
plants.