Flow cytometric identification of two different rhodamine-123-stained mitochondrial populations in maize leaves

Flow cytometric analysis of mitochondria isolated from maize leaves revealed two distinct rhodamine-123-stained fluorescence populations distinguishable by their main fluorescence channel. Further microscopic observation of mitochondria stained with Janus Green B and rhodamine-123 revealed the occurrence of differently sized mitochondrial particles. It was shown by pulsed-field gel electrophoresis that the DNA from the isolated mitochondria ranged in size from 45 to 100 kb. These results suggest that different types of mitochondria with different physiological status, mass, and genomic DNA size probably coexist and carry out different physiological functions throughout the whole process of maize leaf growth and development.