Shoot circumnutation and winding movements require gravisensing cells.
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.
Kitazawa
Daisuke
D
Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
Hatakeda
Yasuko
Y
Kamada
Motoshi
M
Fujii
Nobuharu
N
Miyazawa
Yutaka
Y
Hoshino
Atsushi
A
Iida
Shigeru
S
Fukaki
Hidehiro
H
Morita
Miyo Terao
MT
Tasaka
Masao
M
Suge
Hiroshi
H
Takahashi
Hideyuki
H
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
D010940:Plant Proteins