Yendrek, Craig R. , Li, Tsai-chi , Metzger, James .
CRY1 is Involved in Mediating Leaf Development in Response to Light Intensity.
In plants, the blue light photoreceptor cryptochrome 1 (CRY1) has been shown to play a major role in mediating the early events of photomorphogenesis. In an attempt to further characterize processes influenced by blue light signaling, CRY1 was cloned from Nicotiana sylvestris and was used to generate plants containing elevated levels of CRY1. Compared to wild type seedlings, the overexpression lines had a shorter hypocotyls, while mature plants exhibited a dwarf phenotype that included shorter plant height and smaller leaf surface area. When these plants were grown in low light conditions, the leaves exhibited many features characteristic of sun leaves, including visibly greater leaf thickness, higher specific leaf area, greater content of chlorophyll when expressed on a per unit leaf area basis, and a more “wavy” leaf margin. Analysis of the gross morphology of the leaves revealed additional sun leaf characteristics including a thicker mesophyll with a more tightly arranged palisade layer and a higher stomatal density. These results suggest that the enhanced sensitivity to light resulting from elevated levels of CRY1 altered the plant’s ability to respond to changes in irradiance and support a model that has CRY1 mediating vegetative leaf development in response to increased irradiance. We propose that cryptochrome is an irradiance sensor in contrast to phytochrome B, which senses changes in spectral composition. When considering the functional and physical interaction between cryptochrome and phytochrome, this model is intriguing because it complements phytochrome B-mediated responses to reduced R:FR (shade avoidance) triggered by vegetative shade.
Log in to add this item to your schedule
1 - Univeristy of Vermont, Department of Plant Biology
2 - Ohio State University, Department of Horticulture & Crop Science
3 - Ohio State University, Department of Horticulture & Crop Science, 2021 Coffey Road, Columbus, OH, 43210, USA
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM