Poster: Photomorphogenesis

Abs # 385: De-etiolation is regulated by subtle temperature signals

Presenter:	Finlayson, Scott A, sfinlayson@tamu.edu
Authors	Finlayson, Scott A (A)   Salzman, Ron A (B)   Mullet, John E (B)   Morgan, Page W (A)
Affiliations:	(A): Department of Soil and Crop Sciences,Texas A&M University (B): Department of Biochemistry and Biophysics, Texas A&M University

Environmental cues have a major impact on the growth and development of plants. Plant responses to these conditioning signals determine, in part, the ultimate form and function of the organism. For instance, the response of dark grown plants to subtle light signals is de-etiolation. Although plant responses to subtle light signals have been studied in detail, little is known of the effects of subtle temperature signals on plant growth and development. We have found that de-etiolation, which is typically believed to be controlled by light, is similarly regulated by subtle temperature cues. The grass crops sorghum and maize are particularly sensitive to these signals and show robust responses. We have characterized some of the parameters of the temperature sensing phenomenon and have found that the response is saturable with respect to duration and magnitude of the signal, suggesting it may be sensor mediated. The effects of light and temperature signals delivered concurrently is additive. Temperature sensing and light sensing appear to operate via signaling pathways that are initially independent, but eventually converge to effect similar morphological changes. Expression profiling has identified a number of genes with altered expression to subtle temperature signals. Some of these genes are regulated only by temperature signals while others are regulated by both temperature and light signals. The putative temperature sensor(s) may act in concert with light sensors to ensure that de-etiolation occurs upon emergence from the soil.