토마토 dgt 돌연변이체의 엽병 상편생장에서 (上便生長) 에틸렌에 의한 옥신 감수성의 변화 = Ethylene - Induced Auxin Sensitivity Changes in Petiole Epinasty of Tomato Mutant dgt

다국어 초록 (Multilingual Abstract)

The tomato (Lycopersicon esculentum Mill.) mutant diageotropica (dgt) lacking normal gravitropic response is known to be less sensitive to auxin compared with its isogenic parent VFN8. Straight growth as well as ethylene production in response to added auxin in hypocotyl segments of dgt was negligible. However, there was no significant difference between the two genotypes in auxin transport in petiole segments and its inhibition by the phytotropin N-1-naphthylphthalamic acid(NPA). Kinetic parameters of NPA binding to microsomal membranes were also non-distinguishable btween the two. Its petiolar explants treated with ethylene developed epinastic curvature with the magnituds of response increased about 3 folds over non-mutant wild type. Ethylene-induced epinasty in both dgt and VFN8 was nullified by treatment of explants with the ethylene antagonist 2,5-norbonadiene. Lateral transport of ^3H-IAA toward the upper side of ethylene-treated petioles in dgt, however, was not significantly more pronounced than in VFN8, the implications being that auxin sensitivity in the mutant was restored, or even rised above the wild type, by ethylene.