title: 4,4,4-trifluoro-3-(indole-3-)butyric acid promotes root elongation in Lactuca sativa independent of ethylene synthesis and pH.
abstract: We studied the mode of action of 4,4,4-trifluoro-3- (indole-3-) butyric acid (TFIBA), a recently described root growth stimulator, on primary root growth of Lactuca sativa L. seedlings. TFIBA (100 micromoles) promoted elongation of primary roots by 40% in 72 h but inhibited hypocotyl growth by 35%. TFIBA induced root growth was independent of pH. TFIBA did not affect ethylene production, but reduced the inhibitory effect of ethylene on root elongation. TFIBA promoted root growth even in the presence of the ethylene biosynthesis inhibitor L-alpha-(2-aminoethoxyvinyl)glycine. TFIBA and the ethylene-binding inhibitor silver thiosulphate (STS) had a similar effect on root elongation. The results indicate that TFIBA-stimulated root elongation was neither pH-dependent nor related to inhibition of ethylene synthesis, but was possibly related to ethylene action.
authors.affiliation: Department of Biology, University of Louisiana, Lafayette, LA 70504-2451, USA.
authors.forename: Nenggang
authors.initials: N
authors.lastname: Zhang
authors.forename: Karl H
authors.initials: KH
authors.lastname: Hasenstein
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology; D002087:Butyrates / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005030:Ethylenes / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development; D007210:Indoleacetic Acids / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology*; D018545:Lactuca / Q000187:drug effects* / Q000254:growth & development; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development; D012834:Silver / Q000494:pharmacology; D013885:Thiosulfates / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000613:Aminobutyrates; D002087:Butyrates; D005030:Ethylenes; D007210:Indoleacetic Acids; D007211:Indoles; D010937:Plant Growth Regulators; D013885:Thiosulfates; D012834:Silver; C012175:2-amino-4-(2-aminoethoxy)butanoic acid; C030737:indoleacetic acid; C036216:ethylene