Controlled deterioration treatment (CDT) negatively affects the seed quality and vigor during post-harvest storage. A label-free proteomic approach was utilized to understand the CDT responses in soybean seeds. Soybean seed are rich in seed-storage proteins (SSPs) constituting up to 70 to 80% of the total seed protein content. Due to the presence of these SSPs, it is very difficult to identify and/or characterize the low-abundance regulatory proteins. Availability of appropriate methods for extraction of low-abundance proteins (LAPs) are now providing a platform for the identification of novel proteins involved in the signal perception and transduction during environmental perturbations. To enrich LAPs, the extracted total seed proteins were subjected to protamine sulfate precipitation (PSP) method to deplete SSPs. Fractionated protein fractions thus prepared were analyzed for identification of differential proteins using Label-free quantitative proteomics approaches.