title: Effect of gravity on apical dominance in Pharbitis nil.
abstract: When the upper part of main shoot of morning glory (Pharbitis nil) is gently bent down, lateral bud on the bending region is released from apical dominance and starts to elongate. But, clinorotating the bending shoots prevents the release of the lateral bud from apical dominance. These results suggest that gravity affects apical dominance in morning glory. Here we verified the gravity-regulated apical dominance by using a weeping morning glory defective in gravitropic response due to abnormal differentiation of endodermis. That is, bending main shoot of the weeping morning glory hardly caused the lateral bud to elongate. In addition, decapitation of apical bud released the lateral bud from apical dominance, and exogenous auxin applied to the cut surface of the decapitated stem was inhibitory to the outgrowth of the lateral bud in the wild type. However, the effect of auxin was much less in the weeping morning glory. Thus, apical dominance of the weeping morning glory was weaker and less influenced by gravity than that of the wild type, which could occur due to abnormal differentiation of endodermis required for graviperception.
authors.affiliation: Graduate School of Life Sciences, Tohoku University.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kitazawa
authors.forename: Nobuharu
authors.initials: N
authors.lastname: Fujii
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suge
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D035264:Flowers / Q000187:drug effects / Q000254:growth & development; D006112:Gravitation; D007210:Indoleacetic Acids / Q000494:pharmacology; D027741:Ipomoea / Q000187:drug effects / Q000254:growth & development*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development*
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; C030737:indoleacetic acid