Using longSAGE to study cereal gene expression during grain development and germination

Many methods of studying gene expression rely on previous knowledge of gene sequences to quantify transcript levels. However the SAGE method samples whatever transcripts are present in a given tissue and time point. In one set of experiments we targeted the development of wheat grain using longSAGE. Developing wheat caryopses were sampled for SAGE analysis at five time points - the first at eight days post anthesis and the last being mature grain (40 dpa). A total of approximately 240,000 longSAGE tags were sequenced across these five time points. In another experiment we have targeted germinating barley grain during the malting process across eight time points. From SAGE libraries made from whole caryopses we have sequenced a total of approximately 200,000 longSAGE tags across these eight time points. The results from longSAGE have revealed the expression patterns of a large number of genes across these two time courses. The longSAGE data provides new information on gene expression during these two critical processes in wheat and barley grain.