title: cis-Cinnamic acid selective suppressors distinct from auxin inhibitors.
abstract: The activity of cis-cinnamic acid (cis-CA), one of the allelochemicals, in plants is very similar to that of indole-3-acetic acid (IAA), a natural auxin, and thus cis-CA has long been believed to be an analog of auxin. We have reported some structure-activity relationships studies by synthesizing over 250 cis-CA derivatives and estimating their inhibitory activities on root growth inhibition in lettuce. In this study, the compounds that showed low- or no-activity on root growth inhibition were recruited as candidates suppressors against cis-CA and/or auxin and tested for their activity. In the presence of cis-CA, lettuce root growth was inhibited; however, the addition of some cis-CA derivatives restored control-level root growth. Four compounds, (Z)-3-(4-isopropylphenyl)acrylic acid, (Z)-3-(3-butoxyphenyl)acrylic acid, (Z)-3-[3-(pentyloxy)phenyl]acrylic acid, and (Z)-3-(naphthalen-1-yl)acrylic acid were selected as candidates for a cis-CA selective suppressor they allowed the recovery of root growth from inhibition by cis-CA treatment without any effects on the IAA-induced effect or elongating activity by themselves. Three candidates significantly ameliorated the root shortening by the potent inhibitor derived from cis-CA. In brief, we have found some cis-CA selective suppressors which have never been reported from inactive cis-CA derivatives for root growth inhibition. cis-CA selective suppressors will play an important role in elucidating the mechanism of plant growth regulation.
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Okuda
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukuda
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Fujii
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shindo
mesh_terms: D002934:Cinnamates / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007210:Indoleacetic Acids / Q000037:antagonists & inhibitors*; D018545:Lactuca / Q000187:drug effects* / Q000254:growth & development; D015394:Molecular Structure; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D002934:Cinnamates; D007210:Indoleacetic Acids; C029010:cinnamic acid