#oxidase

The up-regulation of alternative oxidase is an example of retrograde regulation, in which nuclear gene expression responds to changes in organellar status (Figure 12.11). (...) Taken together, these NADH hydrogenases and the NADPH dehydrogenases are likely to make plant respiration more flexible and allow control of specific redox homeostasis of NADH and NADPH in mitochondria and cytosol (see Figure 12.11). (...) Of special importance is the synthesis of ascorbic acid, a central redox and stress defense molecule in plants, by the electron transport chain (see Figure 12.11).

One example of the functional usefulness of the alternative oxidase is its activity in so-called thermogenic flowers of several plant families – for example, the voodoo lily (Sauromatum guttatum).