Poster: Photomorphogenesis

Abs # 386: Green Light Signals Antagonize Aspects of Photomorphogenic Development

Presenter:	Folta, Kevin M, kfolta@mail.ifas.ufl.edu
Authors	Folta, Kevin M (A)   Bies, Dawn H (A)   Lehner, Kevin M (A)
Affiliations:	(A): Plant Celluar and Molecular Biology Program and Horticultural Sciences Department, University Of Florida
Web Site:	http://www.arabidopsisthaliana.com

Classical and contemporary studies show that green light (GL) signals can influence plant growth and development. Recent studies in our laboratory show that GL signals antagonize specific aspects of light development during the transition from growth in darkness to growth in light. Whereas red, far-red, blue and UV light inhibit stem elongation rate during de-etiolation, monochromatic GL causes the stem to elongate more rapidly. The response is not mediated by known photoreceptors. Microarray analyses performed on RNA obtained during the peak of the GL response (1 h after a 10² μmol m^-2 s^-1 pulse) show that this short GL pulse down-regulates accumulation of specific light-induced transcripts. Together these results suggest that an unidentified GL-sensor (or sensors) informs the developing seedling of photosynthetically-unfavorable light conditions, leading to alternative regimes of growth and gene expression.