Professor University of Arkansas Fayetteville, Arkansas, United States
Plant Elicitor Peptides (PEPs) are signaling molecules found throughout higher plants that are generated in response to wounding, pathogen or herbivore attack, and that are released from damaged cells into the extracellular matrix. There, PEPs interact with specific Plant Elicitor Peptide Receptors (PEPRs) on the surface of neighboring cells to activate multiple signaling cascades and modulate growth and defense responses. In this study, we demonstrated that the rhizobacterium Bacillus subtilis can be engineered to express a PEP from soybean (Glycine max) and deliver it to roots, thereby hastening seedling growth and reducing infection by the soybean cyst nematode (Heterodera glycines). We also investigated the potential for intraspecific variation in PEPRs in soybean because this could impact the efficacy of PEP treatments on different cultivars. AlphaFold2 was used to predict the protein structures of the three PEPRs found in soybean and assess their potential interactions with the eight known soybean PEPs. We then examined the predicted amino acid sequences of these three PEPRs in over 500 accessions of cultivated (G. max) and wild (G. soja) soybean to identify mutations that might impact their physical interaction with PEPs. Results suggest diversification in signal perception within soybean, and can help inform the selection of the most tightly conserved PEP-PEPR combinations for nematode management.
