Transgenic Tobacco Plants Expressing Synthetic Peptides: A Functional and Structural Analysis for Pathogen Resistance

The emergence of multidrug-resistant pathogens poses a serious threat to human health and agriculture. Current antimicrobial strategies against phytopathogens are often ineffective, failing to ensure food security while contributing to environmental pollution. Synthetic antimicrobial peptides (AMPs) offer a promising alternative due to their broad-spectrum activity and potential for recombinant production. In this study, we investigated the antibacterial potential of two synthetic peptides, VR18 and KG18, against animal as well as plant phytopathogens. Both peptides showed selective binding to bacterial membranes, while exhibiting no toxicity or allergenicity in animal cells. Using solution-state NMR, we explored how their structure relates to their function in disrupting bacterial membranes. When expressed transgenically in Nicotiana tabacum, VR18 and KG18 conferred resistance to Pseudomonas syringae pv. tabaci—a significant plant pathogen—without interfering with the plant's normal stress responses or metabolic activity. These results underscore the potential of AMPs as a sustainable, in vivo alternative to traditional antimicrobials in agriculture and open the door to broader applications in managing phytopathogenic threats.