**1. Introduction**

Proteomics is one of the most explored areas of research based on global-scale analysis of proteins. It leads to direct understanding of function and regulation of genes. Significant ad‐ vances in the comprehensive profiling, functional analysis, and regulation of plant proteins have not advanced much as compared to model organisms such as yeast, humans etc. The application of proteomic approaches to plants implicates; comprehensive identification of proteins, their isoforms, as well as their prevalence in each tissue, characterizing the bio‐ chemical and cellular functions of each protein and the analysis of protein regulation and its relation to other regulatory networks [1]. Genes of higher eukaryotes (including plants) con‐ tain introns which are large and numerous. Therefore, combinational exon usage originating from complex gene structures results in a multitude of splice variants leading to generation of different protein products from a given gene. Thus, the determination of the comprehen‐ sive pattern of expression of each protein isoform is a challenging task, most importantly for poorly expressed proteins [2].

The two-dimensional gel electrophoresis (2-DE) is used for profiling protein expression in‐ volving separation of complex protein mixtures by molecular charge in the first dimension and by mass in the second dimension. Recent advancement in 2-DE has improved resolu‐ tion and reproducibility but still automation in high-throughput setting is lagging. The alter‐ native approaches like multi-dimensional protein identification technology involving largescale proteomics are able to generate a large catalog of proteins present in complex cell extracts. Further, detection of low abundance proteins using sub-cellular fractionation re‐ duces the complexity of protein extracts. These efforts have successfully characterized nucle‐ ar, chloroplast, amyloplast, plasma membrane, peroxisome, endoplasmic reticulum, cell wall, and mitochondrial proteomes of a model plant, *Arabidopsis*. Although, high-through‐ put technologies have helped in characterization of *Arabidopsis* and other organisms' pro‐

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teomes, characterization of various protein classes including membrane and hydrophobic proteins which are recalcitrant to isolation and analysis is still inaccessible [3].

Food allergy can be a serious nutritional problem in children and adults. Any proteincontaining food has the potential to elicit an allergic reaction in the human population. Antibody IgE-mediated reactions are the most prevalent allergic reactions to food. These responses occur after the release of chemical mediators from mast cells and basophils as a result of interactions between food proteins and specific IgE molecules on the surface of these receptor cells. Eight foods or food groups have been identified as the most fre‐ quent sources of human food allergens and account for over 90% of the documented food allergies worldwide. These foods are milk, eggs, fish, crustaceans, wheat, peanuts, tree nuts and soy [4]. Despite their well-documented allergenicity, soy derivatives continue to be increasingly used in a variety of food products due to their well-documented health benefits. Soybean has also been one of the selected target crops for genetic modification (GM). For example, the artificial introduction of 5-enolpyruvylshikimate-3-phosphate syn‐ thase in soybean crop creates an alternative pathway which is insensitive to glyphosate (most potent herbicide), thus increasing overall crop yield. One of the major concerns regarding the safety of GM foods is the potential allergenicity of the resulting products, namely the possible occurrence of either altered or *de novo* expressed of endogenous aller‐ gens after genetic manipulation. This concern justifies careful plant characterization [5]. Proteomics is one of the powerful approaches allowing rapid and reliable protein identi‐ fication. It can provide information about their post-translational modifications, sub-cellu‐ lar localization, level of protein expression and protein-protein interactions. Despite the importance of soybean and the availability of powerful tools for the analysis of proteins from sub-cellular organelles, and specifically for the identification of allergens, only a lim‐ ited number of reports have been published to date.

Soybean is an important source of protein for human and animal nutrition, as well as a ma‐ jor source of vegetable oil. Although soybean is adapted to grow in a range of climatic con‐ ditions including adverse environmental and biological factors, still it has been affected with respect to growth, development, and global production For instance, drought reduces the yield of soybean by about 40%, affecting all stages of plant development from germination to flowering thus reducing the quality of the seeds. [6]. Several other abiotic stresses, such as flooding, high temperature, irradiation, or the presence of pollutants in the air and soil have detrimental effects on the growth and productivity of soybean. Along with morphological and physiological studies on the responses of plants to stress conditions, several molecular mechanisms from gene transcription to translation as well as metabolites were investigated. Recent advances in the field of proteomics have created an opportunity for dissecting quan‐ titative traits in a more meaningful way. Proteomics can investigate the molecular mecha‐ nisms of plants' responses to stresses and provides a path toward increasing the efficiency of indirect selection for inherited traits. In soybean a comprehensive functional genomics is yet to be performed; therefore, proteomics approaches form a powerful tool for analyzing the functions of complete set of proteins including those involved in stress protection.
