The effect of shoot-bending on the amount of diffusible indole-3-acetic acid and its transport in shoots of Japanese pear

Citation
A. Ito et al., The effect of shoot-bending on the amount of diffusible indole-3-acetic acid and its transport in shoots of Japanese pear, PLANT GR R, 34(2), 2001, pp. 151-158
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
PLANT GROWTH REGULATION
ISSN journal
0167-6903 → ACNP
Volume
34
Issue
2
Year of publication
2001
Pages
151 - 158
Database
ISI
SICI code
0167-6903(200106)34:2<151:TEOSOT>2.0.ZU;2-U
Abstract
The amount of diffusible indole-3-acetic acid (IAA) in shoots of Japanese p ear (Pyrus pyrifolia) decreased when vertical shoots were bent at an angle of 45 degrees. A significant decrease of diffusible IAA was observed one da y after shoot bending (DAB), and the degree of this decrease was larger in the apical region of the shoot than in the basal region. The decrease cause d by the shoot bending increased with the duration of the treatment. The IA A amounts in the bent shoot in the apical, central, and basal segments on 1 DAB were 58.2 +/-6.4%, 92.6 +/-7.6%, and 79.1 +/-7.1% of the control, whil e 43.7 +/-4.1%, 30.8 +/-2.9%, and 39.4 +/-2.5% on 14 DAB. Radiolabelled IAA transport velocity was also examined, but it was not influenced by the sho ot angle in the apical region of the shoot. However, the IAA transport velo city in the basal region decreased. It dropped first on I DAB, but it recov ered to the control level 3 DAB, then it decreased again on 14 DAB. A large increase in ethylene production was observed in the bent shoot, but it see med transient and did not continue for 14 days. These results suggest that the decrease of diffusible IAA amounts may be induced not by the decrease o f IAA transport velocity but by the production/supply of IAA in the apical region.