Genetic modification of respiratory capacity in potato.
Mitochondrial respiration was altered in transgenic potato (Solanum tuberosum) lines by overexpression of the alternative oxidase Aox1 gene. Overexpressing lines showed higher levels of Aox1 mRNA, increased levels of alternative oxidase protein(s), and an unusual higher molecular weight polypeptide, which may be a normal processing/modification intermediate. Evidence suggests that the alternative oxidase protein is further processed/modified beyond removal of the transit peptide. Addition of pyruvate to mitochondria oxidizing succinate or NADH increased the alternative pathway capacity but did not eliminate the difference in the capacity between these two substrates. Induction of alternative pathway capacity by aging of tubers appeared to be more dependent on increased levels of alternative oxidase protein than changes in its oxidation state. In leaf and tuber mitochondria, overexpressing lines possessed higher alternative pathway capacity than the control line, which suggests that changing the alternative oxidase protein level by genetic engineering can effectively change alternative pathway capacity.
Hiser
C
C
Michigan State University-Department of Energy Plant Research Laboratory, East Lansing 28824, USA.
Kapranov
P
P
McIntosh
L
L
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017343:Genes, Plant; D005818:Genetic Engineering; D005822:Genetic Vectors; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology*; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D010101:Oxygen Consumption / Q000235:genetics*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000032:analysis; D018749:RNA, Plant / Q000032:analysis; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism; D014018:Tissue Distribution; D014170:Transformation, Genetic; D000099188:Alternative Oxidase
D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D000099188:Alternative Oxidase