title: Shoot circumnutation and winding movements require gravisensing cells.
abstract: Circumnutation and winding in plants are universal growth movements that allow plants to survive despite their sessile nature. However, the detailed molecular mechanisms controlling these phenomena remain unclear. We previously found that a gravitropic mutant of Japanese morning glory (Pharbitis nil or Ipomoea nil), Shidare-asagao (weeping), is defective not only in circumnutation but also in the winding response. This phenotype is similar to that of the Arabidopsis SCARECROW (SCR) mutant. We therefore investigated whether morning glory SCR (PnSCR) is involved in the weeping phenotype. We found that one amino acid was inserted into the highly conserved VHIID motif in weeping-type PnSCR; this mutation caused abnormal endodermal differentiation. We introduced either the mutant or WT PnSCR into Arabidopsis scr mutants for complementation tests. PnSCR of the WT, but not of weeping, rescued the shoot gravitropism and circumnutation of scr. These results show that both the abnormal gravitropism and the circumnutation defect in weeping are attributable to a loss of PnSCR function. Thus, our data show that gravisensing endodermal cells are indispensable for shoot circumnutation and the winding response and that PnSCR is responsible for the abnormal phenotypes of weeping.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kitazawa
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hatakeda
authors.forename: Motoshi
authors.initials: M
authors.lastname: Kamada
authors.forename: Nobuharu
authors.initials: N
authors.lastname: Fujii
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Miyazawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hoshino
authors.forename: Shigeru
authors.initials: S
authors.lastname: Iida
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Fukaki
authors.forename: Miyo Terao
authors.initials: MT
authors.lastname: Morita
authors.forename: Masao
authors.initials: M
authors.lastname: Tasaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suge
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D005816:Genetic Complementation Test; D018466:Gravity Sensing / Q000502:physiology*; D049915:Ipomoea nil / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D030821:Plants, Genetically Modified
chemical_list: D010940:Plant Proteins