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Promotion of hypocotyl elongation in loblolly pine ( Pinus taeda L.) by indole‐3‐acetic acid
Author(s) -
Carpita Nicholas C.,
Tarmann Kathleen M.
Publication year - 1982
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.1399-3054.1982.tb02278.x
Subject(s) - hypocotyl , elongation , auxin , zeatin , botany , gibberellic acid , fusicoccin , biology , loblolly pine , chemistry , pinus <genus> , biochemistry , cytokinin , germination , materials science , atpase , gene , metallurgy , ultimate tensile strength , enzyme
Elongation of excised loblolly pine ( Pinus taeda L.) hypocotyls was promoted by indole‐3‐acetic acid and the fungal metabolite, fusicoccin. Gibberellic acid, kinetin, zeatin, or zeatin‐riboside were either without effect or promoted elongation only slightly. The most auxin‐responsive tissue was just below the cotyledonary node, and elongation was confined to sections excised from the upper 2 cm of the hypocotyl. Indole‐3‐acetic acid induced elongation rates in the hypocotyl sections equal to those of intact hypocotyls when the sections were excised from young seedlings. Elongation rates decreased in intact hypocotyls before the excised tissues lost responsiveness to the auxin. Hypocotyl elongation in loblolly pine is discussed in relation to hypocotyl elongation in angiosperm species.