title: Two C2H 4-producing systems in cocklebur seeds.
abstract: C2H4 production of the embryonic axes and cotyledons excised from dormant and non-dormant cocklebur (Xanthium pennsylvanicum Wallr.) seeds was examined in relation to ambient O2 tensions. There were two kinds of C2H4-producing systems, quasi-anaerobic and aerobic, in both organs. Regardless of the organ, the former activity was high in the dormant state and, particularly in axes, declined with after-ripening. On the other hand, the latter activity was almost insignificant in the dormant state, but increased with release from dormancy and the non-dormant axes exclusively produced C2H4 through this system. In the cotyledons, however, the former was still predominant even after they were fully after-ripened. Thus, the C2H4-producing systems were different in the seed organ and in the dormancy state.
authors.affiliation: Department of Biological Science, Tohoku University, 980, Kawauchi, Sendai, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Esashi
authors.forename: Y
authors.initials: Y
authors.lastname: Ohhara
authors.forename: K
authors.initials: K
authors.lastname: Kotaki
authors.forename: K
authors.initials: K
authors.lastname: Watanabe