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Relationship of IAA‐oxidase Activity to Gibberellinand IAA‐induced Elongation of Light‐grown Cucumber Seedlings
Author(s) -
Katsumi Masayuki,
Sano Hiroshi
Publication year - 1968
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1968.tb07369.x
Subject(s) - hypocotyl , elongation , auxin , cotyledon , gibberellin , botany , oxidase test , biology , chemistry , horticulture , biochemistry , enzyme , materials science , gene , metallurgy , ultimate tensile strength
The growth and IAA‐oxidase activity of light‐grown cucumber seedlings (cv. Aonagajibae) were investigated in response to GA 3 and IAA. Both GA 3 and IAA induced significant elongation of the hypocotyl. The fresh and dry weights of the hypocotyl increased due to GA 3 or IAA treatment, whereas no significant change was observed in the cotyledons of GA 3 ‐treated seedlings as compared with the controls. The fresh and dry weights of IAA‐treated cotyledons were both lower than those of controls. Treatment with GA 3 or IAA resulted in retardation of IAA‐oxidase activity in the hypocotyl and cotyledons. The degree of retardation was less in the cotyledons than in the hypocotyl. An inverse relationship was recognized between GA 3 ‐ or IAA‐induced elongation and IAA‐oxidase activity in the hypocotyl. The auxin‐mediated mechanism for gibberellin action was discussed.