A multi‐recombination model for the mtDNA rearrangements seen in maize cmsT regenerated plants

• Published in: The Plant journal : for cell and molecular biology 1992-11, Vol.2 (6), p.949-958
• Main Authors: Fauron, Christiane M.‐R., Casper, Mark, Gesteland, Raymond, Albertsen, Marc
• Format: Article
• Language: English
• Subjects: Zea mays
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.1992.00949.x

Summary Regeneration of plants from maize cytoplasmic male sterile type T (cmsT) callus tissue culture promotes, in some instances, genetic variability in their mitochondrial genomes. These mutations have been analyzed in various cmsT regenerated plants that have or have not regained the male fertile phenotype. A unique multi‐recombination model explains the various mitochondrial genome rearrangements. First, recombination involving two different sets of direct repeats gives rise to subgenomic recombinant circles. Second, intermolecular recombination between some selected subgenomes gives rise to a new rearranged master chromosome. The consequence of these events is the formation of a new master chromosome containing sequence deletions and duplications when compared to the progenitor. This new mitochondrial genome seems stable, although it does not contain the entire genetic complexity of the progenitor.