Poster: Regulation of gene expression

Abs # 733: Combining Genomics and Reverse Genetics to Identify Sugar-Response Genes from Arabidopsis

Presenter:	Li, Chunyao , lixxx265@umn.edu
Authors	Li, Chunyao  (A)   Larson, Kat M. (A)   Heisel, Timothy J. (A)   Zanol, Michelle  (A)   Pattison, Donna  (A)   Gibson, Susan I. (A)
Affiliations:	(A): University Of Minnesota

Soluble sugars play an important role in modulating plant development, metabolism and gene expression. Sugar-response pathways are also thought to help regulate interactions between sources and sinks of fixed carbon, thereby affecting carbon partitioning and, ultimately, crop yields. Very few factors involved in sugar response pathways have been identified so far. We are employing a combination of genomics and reverse genetics approaches to identify components of sugar response pathways from Arabidopsis. Affymetrix GeneChips representing approximately 90% of the Arabidopsis genome have been used to identify sugar-regulated genes from germinating seeds and adult plants. In addition, we have also used Chips to identify ABA, ethylene and GA-regulated genes in germinating seeds. These experiments represent one of the most extensive sets of transcriptional profiling studies conducted to date. Based on these studies, target genes that may encode components of sugar-response pathways in germinating seeds have been identified. These genes were selected using two criteria. 1) Genes that are significantly regulated by glucose and/or sucrose, but not by sorbitol or, in most cases, by ABA. 2) Genes that are predicted to encode proteins with activities commonly associated with response pathways, such as transcription factors, protein kinases and protein phosphatases. T-DNA insertion lines representing most of the target genes have been obtained and are being characterized. Initial results indicate that mutations in some of the target genes do, in fact, alter sugar response. Identifying and characterizing sugar response genes will provide us with useful information that will aid in establishing a general picture for sugar response networks in plants.