Whole-genome sequencing and identification of antimicrobial peptide coding genes in parsley (Petroselinum crispum), an important culinary and medicinal Apiaceae species

Parsley is a commonly cultivated Apiaceae species of culinary and medicinal importance. Parsley has several recognized health benefits and the species has been utilized in traditional medicine since ancient times. Although parsley is among the most commonly cultivated members of Apiaceae, no systematic genomic research has been conducted on parsley. In the present work, parsley genome was sequenced using the long-read HiFi (high fidelity) sequencing technology and a draft contig assembly of 1.57 Gb that represents 80.9% of the estimated genome size was produced. The assembly was highly repeat-rich with a repetitive DNA content of 81%. The assembly was phased into a primary and alternate assembly in order to minimize redundant contigs. Scaffolds were constructed with the primary assembly contigs, which were used for the identification of AMP (antimicrobial peptide) genes. Characteristic AMP domains and 3D structures were used to detect and verify antimicrobial peptides. As a result, 23 genes (PcAMP1-23) representing defensin, snakin, thionin, lipid transfer protein and vicilin-like AMP classes were identified. Bioinformatic analyses for the characterization of peptide physicochemical properties indicated that parsley AMPs are extracellular peptides, therefore, plausibly exert their antimicrobial effects through the most commonly described AMP action mechanism of membrane attack. AMPs are attracting increasing attention since they display their fast antimicrobial effects in small doses on both plant and animal pathogens with a significantly reduced risk of resistance development. Therefore, identification and characterization of AMPs is important for their incorporation into plant disease management protocols as well as medicinal research for the treatment of multi-drug resistant infections.