Divergence of Catalase and Respiration in Germination

Abstract

1. Catalase decreases in early germination stages in six kinds of seeds tested. The initial decrease is followed by the rise generally reported for germination. 2. Catalase decreases slowly, almost to exhaustion in prolonged soaking of seeds in oxygen-free water. 3. There is a decrease of catalase in both the embryo and the endosperm of germinating wheat. The subsequent rise occurs not only in the embryo but also in the endosperm, although in a much less marked degree. 4. A simple respirometer is described, in which large quantities of material can be used, and consecutive readings taken at will on the same sample. By direct reading of the manometers both the oxygen and carbon dioxide can be determined without titration and with practically no calculation. 5. There is a large and immediate rise in respiration when seeds are put in germinating conditions. The early curve of respiration, therefore, diverges widely from the typical germination curve of catalase. 6. Catalase in ripening seeds decreases per un...