Seed Proteomics Approach for Identifying of Sorghum Genotypes by Using 2-Dimensional Gel Electrophoresis and MALDI-TOF-Mass Spectrometry

In the last years, proteomics analyses in cereals have significantly increased but few studies have been performed in sorghum. Sorghum seed proteomics investigation not only potential markers for identifying of among genotypes but also their nutritional aspects and utilizing in the breeding programs. However, we reported here a proteomics approach for different sorghum genotypes by using two-dimensional gel electrophoresis (2-DGE) and Matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). A comprehensive proteomics analysis were therefore attempted using mature seed of six sorghum genotypes i.e., IS 3477, IS 33095, IS 7005 (non pigmented), IS 2898, IS 7155, IS 1202 (pigmented). The six high resolution gels of 2-Dimensional gel electrophoresis (2-DGE) stained with coomassie brilliant blue (CBB) which were enabled a total of 600 above protein spots including the pigmented lines were shown below 100 whereas non pigmented lines were exhibited above 100 protein spots. The protein spots of each genotype were well separated based on their molecular weight and pI values which ranges between 12-90 kDa and 4-9.5 respectively. A total of fourteen identical protein spots were selected from the six genotypes pertaining 4 common spots and 10 specific spots, showing a notable change, were sequenced by MALDI-TOFMS analyzer. Unfortunately, out of the seed responsive fourteen protein spots, eight protein spots annotated to sorghum and orthologs from other monocots such as maize, rice, and barley. Most of the identified proteins belongs to seed storage protein, Heat shock protein, RNA binding & zinc finger proteins, carbohydrate metabolism and hypothetical proteins. This study would be of interest to use these proteins to develop quick test for seed quality as well as gene annotation.