Skip Navigation



JXB Advance Access published online on June 23, 2006
Journal of Experimental Botany, doi:10.1093/jxb/erj210
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
57/10/2379    most recent
erj210v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Christophe, A.
Right arrow Articles by Varlet-Grancher, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Christophe, A.
Right arrow Articles by Varlet-Grancher, C.
Agricola
Right arrow Articles by Christophe, A.
Right arrow Articles by Varlet-Grancher, C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Published by Oxford University Press [2006] on behalf of the Society for Experimental Biology.
Received October 17, 2005
Accepted March 22, 2006

RESEARCH PAPER

Quantitative contributions of blue light and PAR to the photocontrol of plant morphogenesis in Trifolium repens (L.)

Angélique Christophe 1 *, Bruno Moulia 2, and Claude Varlet-Grancher 3

1 Unité d'Ecophysiologie des Plantes Fourragères, INRA, Lusignan, F-86600, France; Present address: Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux, UMR INRA - ENSAM, place Viala, F-34060 Montpellier cedex 1, France
2 Unité d'Ecophysiologie des Plantes Fourragères, INRA, Lusignan, F-86600, France; Present address: UMR PIAF, INRA, Site de Crouël, 234 avenue du Brézet, F-63039 Clermont-Ferrand cedex 02, France
3 Unité d'Ecophysiologie des Plantes Fourragères, INRA, Lusignan, F-86600, France

* To whom correspondence should be addressed.
Angélique Christophe, E-mail: christop{at}ensam.inra.fr


  Abstract

Shade-avoidance is a major adaptive response of plants, and is usually considered to be controlled by phytochromes through the perception of changes in the red:far red light ratio. However, few studies on the effects of blue light (BL) and of light intensity [photosynthetically active radiation (PAR)] on light-grown plants have been conducted, especially concerning changes in PAR at constant BL. The objective here was to quantify the photocontrol of aerial morphogenesis by BL and PAR. Experiments were conducted varying BL and PAR independently, with three BL levels (4, 38, and 83 µmol m-2 s-1) at constant PAR (300 µmol m-2 s-1) and three PAR levels (338, 705, and 163 µmol m-2 s-1) at constant BL (36 µmol m-2 s-1). Effects on morphogenetic processes were analysed as quantitative modulations of ontogenic trends and response curves were produced. White clover (Trifolium repens L.) was used, as it is a typical shade-avoider displaying the whole syndrome of shade-avoidance in a purely vegetative stage. Morphological responses were strongly controlled by both BL and PAR changes, through antagonist effects on leaf appearance rate and additive effects on petiole elongation. All the other responses appeared to be the indirect consequences of changes in the leaf appearance rates. BL acted as a light signal for plant morphogenesis. However, the PAR control probably implicates two distinct mechanisms, such as a trophic effect and a signal. Both PAR and BL actions involved organ-specific differences, which are central in the control of the shade-avoidance responses.

Keywords: Blue light; leaf appearance rate; PAR; petiole growth; photomorphogenesis; plasticity; shade-avoidance; Trifolium repens L.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.