Title

Apical Control, Gravitropic Signaling, and the Growth of Lateral Roots in Arabidopsis

Document Type

Article

Publication Date

2005

Publication Title

Advances in Space Research

Volume Number

36

Issue Number

7

DOI

10.1016/j.asr.2005.03.103

Abstract

Most research on gravity responses in plants has focused on primary roots and shoots, which typically grow in a vertical orientation. However, the patterns of lateral organ growth, which generally have large effects on overall plant architecture, are such that the organs are typically not vertical. In lateral roots of Arabidopsis, growth is initially in a nearly horizontal orientation but changes to a near-vertical orientation as the lateral root develops. Although the non-vertical lateral roots are gravitropically competent, following gravitropic reorientation of seedlings, the lateral roots on the upper flank of the primary root have different growth patterns from those on the lower side of the primary root. The differences are in part dependent on reorientation of the primary root, suggesting that gravitropic signaling from the primary root also contributes to the control of lateral root growth. The hormone auxin appears to play a role in this signaling between the primary and lateral roots, as auxin transport inhibitors applied to the primary root affect lateral root growth. Also, lateral roots of pin3 mutants, which are impaired in polar auxin transport, have altered lateral root orientations. However, other signals from the primary root tip also play an important role in regulating lateral root growth.

ISSN

0273-1177

First Page

1211

Last Page

1217

Link Out URL

https://doi.org/10.1016/j.asr.2005.03.103

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