The respiration of healthy wheat seedings is mediated largely by Fe-containing enzymes. By contrast, the enormously increased O2 up-take of tissues infected with stem rust is highly sensitive to Cu-chelating agents. The presence of polyphenolases could not be detected. Cytochrome oxidase was ruled out as a possible source of ascorbic acid oxidation. The tissues yielded, however, very active ascorbic oxidase. Increase in ascorbic oxidase activity parallels the respiratory increase in diseased plants. It is concluded, therefore, that the major role of Fe catalysis in healthy plants will be replaced in a very short time by Cu catalysis in infected ones.
ASJC Scopus subject areas
- Molecular Biology