Gene content and organization of the oat mitochondrial genome

The physical organization of the oat mitochondrial genome has been establis hed. The master chromosome, one of the most complex described so far among higher plants, accounts for 596 kb and contains six direct repeats. Reitera ted inverted repeats of 12 and 3 kb are also present and imply the possible existence of multiple isomeric forms. Fourteen genes coding for proteins, components of chain respiration and oxidative phosphorylation complexes, an d of mitochondrial ribosomes have been detected together with rrn26, rrn18 and rrn5 genes and a set of 18 tRNA genes (ten genuine and eight cp-like). Some of them are clustered in a conserved form with respect to other monoco ts. Only the trnS (GGA) gene is silent.