Identification and characterization of antimicrobial peptides from Feijoa sellowiana transcriptome

Antimicrobial peptides (AMPs) are small polypeptides present in a wide diversity of phylogenetically distant organisms, including plants. They are part of the innate immune response, allowing rapid action at a lower energetic cost than the adaptive immune system. Various applications of these peptides as anti-infective agents have been demonstrated. Despite their significant potential, the initiatives for bioprospecting of AMPs from the native flora of Uruguay are still incipient. The aim of this study was to identify and characterize genes encoding six antimicrobial peptides families, comprising: defensins, snakins, thionins, hevein-like, lipid transfer proteins (LTPs), and cyclotides in the native fruit species Feijoa sellowiana (Myrtaceae), commonly known as guayabo del país or feijoa. The search was carried out using BLAST, based on a de novo transcriptome of leaf and flower, utilizing reference sequences. The relationships between F. sellowiana and reference protein sequences were characterized through multiple alignments and phylogenetic analysis. The exon-intron structure and isoforms of F. sellowiana AMPs were analyzed by PCR amplification in genomic DNA. This study identified 23 defensins, 49 snakins, 7 thionins, 12 hevein-like and 87 LTPs; no evidence of cyclotide transcripts was found. The expected exon-intron structure was confirmed for five sequences, belonging to defensins, snakins, and hevein-like families.