The Oxygen Consumption of Isolated Woody Tissues

• Published in: American journal of botany Vol. 27; no. 4; pp. 234 - 237
• Main Authors: Goodwin, Richard H., Goddard, David R.
• Format: Journal Article
• Language: English
• Published: American Botanical Society 01-04-1940
• Subjects: Budbreak; Cambium; Nitrogen; Oxygen; Oxygen consumption; Phloem; Plant tissues; Sapwood; Tree trunks; Xylem
• ISSN: 0002-9122; 1537-2197
• DOI: 10.1002/j.1537-2197.1940.tb14676.x

Thin sections of tissues were cut from the trunks of ash and maple trees and their oxygen consumption was measured. In trees collected before bud break oxygen consumption is most rapid in the cambial region. Values for the adjacent secondary phloem and xylem are somewhat lower. In the xylem oxygen consumption becomes progressively lower as one passes toward the center of the tree. In the heartwood there is a very low basal rate of oxygen consumption which is not destroyed by boiling. This is probably due to a slow oxidation of organic compounds in the dead cells. Phloem and sapwood exhibit similar oxidations of comparable magnitude after boiling. After bud break the oxygen consumption of the cambium, phloem and heartwood of Fraxinus is essentially the same as before bud break. In the newly-formed, differentiating xylem, however, it appears to exceed considerably the cambial rate. The above relations remain essentially the same whether oxygen consumption is expressed per gram wet weight or per milligram of nitrogen.