Plant Mitochondrial-Targeted Gene Delivery by Peptide/DNA Micelles Quantitatively Surface-Modified with Mitochondrial Targeting and Membrane-Penetrating Peptides

Plant mitochondria play essential roles in metabolismand respiration.Recently, there has been growing interest in mitochondrial transformationfor developing crops with commercially valuable traits, such as resistanceto environmental stress and shorter fallow periods. Mitochondrialtargeting and cell membrane penetration functions are crucial forimproving the gene delivery efficiency of mitochondrial transformation.Here, we developed a peptide-based carrier, referred to as Cytcox/KAibA-Mic,that contains multifunctional peptides for efficient transfectioninto plant mitochondria. We quantified the mitochondrial targetingand cell membrane-penetrating peptide modification rates to controltheir functions. The modification rates were easily determined fromhigh-performance liquid chromatography chromatograms. Additionally,the gene carrier size remained constant even when the mitochondrialtargeting peptide modification rate was altered. Using this gene carrier,we can quantitatively investigate the relationships between variouspeptide modifications and transfection efficiency and optimize thegene carrier conditions for mitochondrial transfection.