Submitted to: Physiologia Plantarum
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/28/2004
Publication Date: 2/1/2005
Citation: Beilinson, V., Moskalenko, O.V., Ritchie, R.D., Nielsen, N.C. 2005. Differentially expressed genes during seed development in soybean. Physiologia Plantarum. 123:321-330. Interpretive Summary: An important developmental event during seed development causes cotyledonary cells to stop dividing, and instead enlarge as massive amounts of storage oils and proteins become accumulated. The timing of this event is genetically controlled, but the genes involved are unknown. To identify these genes, messenger RNAs that appear in seeds just before and just after the initiation of seedfill were cloned. Then libraries of clones from before and after seedfill were subtracted from one another to eliminate those that were common to both libraries. This manuscript describes the construction of the libraries, and characterizes the clones that remained after subtraction. Included in the subtraction libraries were clones that encoded proteins potentially involved in signal transduction pathways or putative DNA binding proteins. Studying these genes may provide clues about how the initiation of seedfill is controlled.
Technical Abstract: Little reliable information exists about the genetic events that control the onset and timing of seed fill in soybean cotyledons. To identify genes involved in this process, cDNA libraries were prepared from mRNAs isolated from seeds at 7 and 22 days after flowering. which represent times just before and after the initiation of seed-fill. For the soybean variety Resnik, which was used for this study, seed-fill and the establishment of an endoreduplicative cell cycle occurs 12-14 DAF. Suppression Subtractive Hybridization was then applied to identify sequences that are differentially expressed at each of these two developmental stages. False positives in the libraries were reduced by using mirror orientation selection (MOS). The libraries of differentially expressed genes that resulted were analyzed, and the nucleotide sequences obtained compared with those in existing databases. Several genes from each library were chosen and their expression profile during seed development was analyzed by quantitative RT-PCR using RNA preparations originating from different seed developmental stages. Candidate genes for control of the stage shift from dividing cells to endoreduplication were identified.