Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/1997
Publication Date: N/A
Citation: Interpretive Summary: Soybean seed embryos produce large amounts of some proteins during development. The proteins produced during the final stage of embryo development are called late embryogenic abundant proteins'. It is thought that these proteins play a role in allowing the seed to dry up at later stages of maturity, without biological damage to the embryo. These researchers identified the entire family of genes responsible for producin these proteins in soybean and determined the location of each of the genes on chromosomes. By looking at when these genes were active the authors determined that the families could be placed in two groups, each perhaps representing an ancient ancestor of the soybean. This work may help researchers understand more about the evolution of soybean as a major crop.
Technical Abstract: The entire Em-like group 1 Late Embryogenesis Abundant (Lea) gene family from soybean was cloned and characterized. The five Group 1 Lea genes (Sle1-5) were divided into two classes based on sequence identity. Sle1-4 were genetically mapped to four different linkage groups. Nucleotide sequencing indicated that Sle1, Sle2, Sle3, and Sle5 encode polypeptides differing primarily by the presence of a repeated 20-amino acid motif. Sle1 and Sle5 were shown by Northern analysis to be expressed in developing embryos weeks earlier than Sle2 and Sle3. Sle4 was shown to be a pseudogene. Maximal levels of mRNA for all functional Sle genes accumulated in maturation phase seeds, before significant desiccation had occurred, and declined rapidly upon seed imbibition. Desiccation did not induce Sle expression in seeds or vegetative tissue. Sle expression was confined to embryo tissues and Sle mRNA accumulated at similar levels in both the embryo axis and in the cotyledons.