As well as the expressionof quite a few genes involved in salicylic acid, jasmonic acid
Plus the expressionof numerous genes involved in salicylic acid, jasmonic acid, and ethylene-signaling pathways in tomato plants (Robatzek et al., 2007; Caravaca-Fuentes et al., 2021). Our group has developed several families of peptides derived from all-natural compounds or de novo created. Our aim was to find short sequences with high antimicrobial activity, low toxicity, and high stability to protease degradation (Montesinos et al., 2012). In specific, we made and synthesized a library of linear P2Y6 Receptor Storage & Stability undecapeptides (CECMEL11) (Ferret al., 2006; Badosa et al., 2007), from which we identified sequences with a fantastic biological activity profile that have been applied effectively to handle diseases caused by fungal and bacterial plant pathogens of economic importance (Badosa et al., 2007, 2009; Baret al., 2020). Many peptide conjugates from members of your CECMEL11 library, like BP358 (containing flg15 and BP16), showed antimicrobial and plant defense elicitation activities inside the Erwinia amylovora/pear pathosystem (Caravaca-Fuentes et al., 2021). Furthermore, we designed a family of hybrid peptides to become produced in plant systems. Among them, BP178 (KKLFKKILKYL-AGPA-GIGKFLHSAK-KDEL-OH), incorporating BP100 (KKLFKKILKYL), magainin (10), an AGPA hinge for connecting both, and a KDEL endoplasmic reticulum retention signal, exhibited a powerful bactericidal impact against quite a few plant pathogenic bacteria as well as a quite slight toxicity, but gave an HR-type reaction in tobacco leaves (Badosa et al., 2013). The peptide was expressed inside the transgenic rice seed endosperm and protected seedlings from bacterial infection, but the protective impact was not totally explained by its antimicrobial properties (Montesinos et al., 2017). Inside the present study, we planned to elucidate the mechanism of action of BP178 and whether it truly is able to trigger plant defense responses in tomato as a model plant. Specifically, the aim of this work was to establish if the topical application with the peptide to plants (1) protects against bacterial and fungal infection and (2) induces defense and stress-related gene expression. The impact of BP178 was in comparison with the plant defense elicitor peptide flg15, which has no antimicrobial activity, and towards the parent bactericidal undecapeptide BP100 with bactericidal but no defense elicitor activity.Components AND Methods Bacterial and Fungal Strains and Growth ConditionsThe bacterial pathogens Xanthomonas campestris pv. vesicatoria Xcv206 (Xcv) (D. F. Ritchie, Division of Plant Pathology, North Carolina State University) and NOD2 custom synthesis Pseudomonas syringae pv. tomato DC3000 (Pto) (J. Murillo, Plant Pathology, Public University of Navarra, Spain), along with the necrotrophic fungus Botrytis cinerea (Bc) (CECT 20518) have been utilized. Bacterial strains were cultured in LB agar for 24 h at 28 C and scrapped in the surface to prepare suspensions adjusted to 108 CFU/ml. Bc was grown on potato dextrose agar (PDA) for ten days at 23 C. Spores had been collected by spreading sterile distilled water containing 0.01 (v/v) tween-20 onto the surface on the plate. The sporeFrontiers in Plant Science | www.frontiersinOctober 2021 | Volume 12 | ArticleMontesinos et al.BP178 Bactericidal and Elicitor Peptidesuspension was filtered by way of three layers of sterile cheesecloth and adjusted to five 105 spores/ml.Synthesis of PeptidesPeptides BP178 (KKLFKKILKYLAGPAGIGKFLHSAKKDELOH), flg15 (RINSAKDDAAGLQIA-OH), and BP100 (KKLFKKILKYL-NH2 ) had been synthesized making use of the solid phase.