Plant vs Animal Mitochondrial DNA

[Diana.Keirstead]

I know that plants have a much larger mitochondrial DNA than animals but does anyone know why this is the case? Also what other mitochondrial differences are there between them? And why do they exist?

Thanks,
Diana

[honee_v]

one reason why mitochondrial genome in plants is larger than in animals becoz it encodes not only for proteins (e.g. ATPase, etc) for cell respiration but also for cytoplasmic male sterility in certain plants, like corn...


if you like you can read this article: http://www.biology-online.org/articles/mitochondrial_functions_higher_plants.htm


^_^

[honee_v]

there are basically 3 differences (AFAIK)... and uve mentioned one already...

another is the presence of NADH dehydrogenase (it is an enzyme) structurally intact in the inner mitochondrial membrane, facing the intermembrane space... what it does is it catalyze the oxidation of external NADH (that is from the cytosol) ... this ability to oxidise 'external' NADH while the enzyme is structurally intact is common in plant tissues but not in animals...

another is... plants have an alternative pathway for oxidation of substrates... there is an "alternative oxidase" (its another protein found in inner membrane) that allows electron flow to continue even when Complex IV (or cytochrome oxidase) is blocked by cyanide... this ability (of plants) is called "cyanide-insensitive respiration"...


^_^