Unlocking Plant-Pathogen Mysteries: How Bacterial Epitope Variation Drives Prediction and Dissection of Outcomes

The bacterial epitopes flagellin (flg22 & flgII-28), ribosome (elf18), and cold shock proteins (csp22) are recognized by plants, triggering defense responses. This study explores the natural evolution and immunogenicity of 90 elf18 and csp22 epitope variants on Arabidopsis and tomato. Through genetic and biochemical analyses, we uncovered a mechanism for pathogen immune evasion, intrabacterial antagonism, where a non-immunogenic epitope blocks perception of immunogenic forms encoded in a single genome. Additionally, we revealed the predictable nature of epitope outcomes, which can be used to rapidly predict receptor utility for emerging pathogens and laying the foundation for immune receptor engineering.