Mitochondrial, plastidial and nuclear DNA content in plants with altered expression of atwhy2. A. DNA gel blot analysis of mitochondrial, plastidial and nuclear genes. 10 μg of total DNA digested with the indicated restriction enzymes were separated on a 1% agarose gel, blotted onto a nylon membrane and hybridized with probes representing the indicated genes. Numbers on the left indicate the molecular weight of the observed bands in kilobasepairs (Kb) as predicted by restriction mapping of mtDNA. B. Ratio of mitochondrial to nuclear genomes was evaluated by Quantitative Real-Time PCR using 2 different mitochondrial gene regions and a single nuclear genome region. The mt/nuclear DNA ratio of Col-0 plants was arbitrarily fixed as 100%.