Cytochrome c Oxidase, the Terminal Oxidase of Iris pseudacorus L.

Abstract

WHILE it is generally agreed that cytochrome c oxidase is the terminal oxidase of embryonic plant tissues, some workers doubt if it has this role in older plant tissues as well¹. It is of interest that a mature tissue such as the rhizome of Iris pseudacorus L., obtained from a Lancashire marsh, should contain a cytochrome system which might reasonably be claimed to account for the oxygen uptake of the tissue. The rhizome tissue used was cut from within the endodermis of the current year's growth, 1.0 cm. or farther from the meristematic region. The cells were typical parenchymatous cells except that the tissue also contained some vascular cells.