Proteomic profiling of fast neutron-induced soybean mutant unveiled pathways associated with increased seed protein content

Authors: ISLAM, NAZRUL - Oak Ridge Institute For Science And Education (ORISE); Krishnan, Hari; Natarajan, Savithiry - Savi

Submitted to: Journal of Proteome Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/12/2020
Publication Date: 8/21/2020
Citation: Islam, N., Krishnan, H.B., Natarajan, S.S. 2020. Proteomic profiling of fast neutron-induced soybean mutant unveiled pathways associated with increased seed protein content. Journal of Proteome Research. 19:3936-3944. https://doi.org/10.1021/acs.jproteome.0c00160.
DOI: https://doi.org/10.1021/acs.jproteome.0c00160

Interpretive Summary: The high nutritional value of soybeans makes it useful for animal feed, and soybean oil is useful for cooking and for food processing. Continued improvement in food quality traits of soybean will help sustain the commercial importance of this crop. In this study, scientists at USDA-ARS evaluated a soybean variety with a 15% increase in seed protein content. The variety, created by bombarding the seeds with fast neutrons, was expected to have undergone genetic rearrangement. The scientists used DNA chip technology and found that the variety was missing 24 genes on chromosomes 5, 10, and 15. Among the genes was a transcription factor gene that controls and regulates the expression of other genes in soybeans. The scientists then used mass spectrometry, an analytical technique, to measure 3,500 proteins in the seeds and found alterations in a network of proteins that control metabolic pathways, including protein synthesis. The scientists hypothesize that the deletion of a transcription factor, along with other several genes, may have altered the negative regulation of protein syntheses processes, resulting in an increase in the overall protein content of the seed. These findings will facilitate the ongoing efforts of scientists and breeders to improve both the quantity and quality of soybeans. Increased quality traits will benefit the overall utilization of soybean in the food and feed industries.

Technical Abstract: Mutagenesis through fast neutrons (FN) radiation in soybean resulted 15% increase in seed protein content of a mutant. A comparative genomic hybridizations (CGHs) analyses confirmed that the mutant is lacking 24 genes located at chromosome 5, 10, and 15. A proteomic profiling of FN mutant revealed differential accumulation of 3,502 proteins, of which 206 protein exhibited increased abundance and 214 decreased abundance. Among the abundant proteins, basic 7S globulin increased four-fold, followed by vacuolar-sorting receptor and protein transporters. The differentially expressed proteins were mapped on a Global Metabolic Pathways and unveiled how protein synthetic pathways are enriched starting from translation initiation factors, ribosomal proteins, endoplasmic reticulum proteins, and finally to the vacuolar protein. The deletion of the gene for a sequence-specific DNA binding transcription factor along with other 23 genes might have a cascading effect on protein synthesis, resulting in an increased amount of total protein content in the soybean seeds.