Unlocking the mysteries of malting using SAGE

Barley and its malting potential are of great economical importance worldwide. The processes involved in malting at the genetic level are however still poorly understood. By examining the transcripts expressed at any time in the cell it is possible to determine which genes and their related proteins are being expressed at that precise moment in time. SAGE (Serial Analysis of Gene Expression) is a technique that allows rapid, detailed analysis of thousands of transcripts in a cell. The abundance of a particular tag relates directly to the expression level of the gene from which it is derived. The analysis of gene expression of different physiological states provides both qualitative and quantitative information. In this study the gene expression profile of germinating (malting) barley is being examined at seven intervals over a time course of 120 hours post steeping. The varieties compared in this study are Tallon and Gairdner which vary considerably in their malting qualities. These post steeping time points will also be correlated with the gene expression profile of dry unsteeped seed. Analysis has revealed 197333 tags corresponding to 59931 unique transcripts. An average of 95% of all tags matched to an annotation within the database. The libraries of Gairdner at 24 hours and Tallon at 12 hours were most similar of all pair wise time point comparisons of significantly differentially expressed transcripts. Genes for improved malting quality can be identified and examined using SAGE and ultimately used for commercial improvement.