Antimicrobial Activity of Glycoalkaloids From <i>Solanum</i> spp. and Their Potential for Control of <i>Dickeya solani</i> and <i>Pectobacterium brasiliense</i>

ABSTRACT Bacterial pathogens such as Dickeya solani and Pectobacterium brasiliense pose a significant threat to global food security by affecting major crops such as potato ( Solanum tuberosum ). Understanding the interaction between plant‐derived molecules and bacterial virulence mechanisms is crucial for disease management strategies. This study investigated the effects of glycoalkaloids (GAs) extracted from the leaves of various potato ( Solanum spp.) forms both directly (on bacterial growth and viability) and indirectly (on pectinolytic activity, biofilm formation and quorum‐sensing [QS] gene expression). In vitro tests revealed that GAs significantly decreased bacterial cell multiplication factors and increased their death, which consequently inhibited pectinolytic activity and biofilm formation in D. solani and P. brasiliense . GAs from Solanum chacoense and cv. Tajfun were associated with significantly reducing QS‐regulated gene expression, specifically in the expI , expR and virulence factor‐modulating (Vfm) QS genes. GAs from the potato DG 00‐683 showed the strongest association with the inhibition of biofilm formation. In addition, the greening of tubers cv. Tajfun, a process that increases the concentration of GAs, resulted in a significant reduction in tuber maceration after inoculation with bacteria, confirming their significant effect on pectinolytic bacteria. This study highlights the potential of Solanum ‐derived GAs as natural pesticides that enhance defence mechanisms in potato tubers against pectinolytic bacteria.