Mass spectrometry guided by transcriptomics reveals multiple classes of predicted antimicrobial peptides in Amaranthus tricolor

Traditional medicinal plants are rich reservoirs of antimicrobial agents, including antimicrobial peptides (AMPs). Herein, Amaranthus tricolor AMPs predicted in silico are identified via proteomics profiling. Bottom-up proteomics identified seven novel peptides spanning three AMP classes including lipid transfer proteins, snakins and defensins. Characterization via top-down peptidomic analysis of Atr-SN1, Atr-DEF1, and Atr-LTP1 revealed unexpected proteolytic processing and enumerated disulfide bonds. These results highlight the potential for integrating AMP prediction algorithms with complementary -omics approaches to accelerate characterization of biologically relevant AMP peptidoforms.