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Effect of light in the control of growth by auxin and its inhibitor(s) in the sunflower
Author(s) -
Muir Robert M.,
Zhu Liangji
Publication year - 1983
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.1399-3054.1983.tb02760.x
Subject(s) - auxin , coleoptile , helianthus annuus , avena , bioassay , sunflower , biology , hypocotyl , botany , helianthus , achene , horticulture , biochemistry , genetics , gene
Diffusates from the hypocotyl and leaves of sunflower seedlings ( Helianthus annuus L. cv. Mammoth) contain both auxin and inhibitor(s) of auxin‐induced growth. The auxin activity has been evaluated with the conventional Avena coleoptile bioassay employing negative curvature, The inhibitor activity has been determined with a newly developed bioassay, measuring the positive curvature response of the Avena coleoptile. This bioassay has been standardized by the response to 2,3,5‐triiodo‐benzoic acid. Diffusates from plants in darkness have higher auxin activity and lower inhibitor activity than diffusates from plants in light. Irradiation at 730 nm promotes auxin synthesis in leaves, and! irradiation at 660 nm promotes synthesis of the inhibitor.