Related Experiment Video
Updated: May 31, 2026

Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana
Published on: May 29, 2010
Stem cell activation by light guides plant organogenesis
Saiko Yoshida1, Therese Mandel, Cris Kuhlemeier
1Institute of Plant Sciences, University of Bern, CH-3013 Bern, Switzerland.
Light signals control leaf initiation and positioning in plants. This process, previously thought autonomous, is regulated by plant hormones cytokinin and auxin in response to light cues.
Area of Science:
- Plant Biology
- Developmental Biology
- Hormone Signaling
Background:
- Leaf initiation occurs at the shoot apical meristem, shielded by older leaves.
- Leaf development has been traditionally viewed as an autonomous process, independent of environmental factors.
Purpose of the Study:
- To investigate the role of light as a morphogenic signal in leaf initiation.
- To elucidate the hormonal mechanisms underlying light-mediated leaf development.
Main Methods:
- Studied leaf initiation in tomato shoot apices under varying light conditions (light vs. dark).
- Analyzed the effects of light and dark treatments on plant hormone levels and localization.
- Investigated the subcellular localization of the auxin transporter PIN1.
Main Results:
- Leaf initiation in tomato ceases in the dark and resumes in the light.
- Light-mediated leaf initiation is regulated by the plant hormone cytokinin.
- Darkness alters the subcellular localization of PIN1, affecting auxin maxima formation.
Conclusions:
- Light acts as a crucial environmental cue controlling leaf initiation and positioning.
- Cytokinin is essential for shoot apical meristem propagation.
- Auxin redirects cytokinin-induced meristem growth towards organ formation.
- Light regulates lateral organ initiation by modulating both auxin and cytokinin signaling pathways.
Related Concept Videos
Cell Signaling in Plants
Photoreceptors and Plant Responses to Light
Morphogenesis
Meristems and Plant Growth
Cell Adhesion in Plants
Pectins are complex heteropolymers mainly composed of negatively-charged α-D-glucopyranosyl uronic acid and some neutral glycosyl residues such as α-L-rhamnopyranose, α-L-arabinofuranose, and...
Somatic to iPS Cell Reprogramming

