Genome-wide in-silico evaluation of pathogen-related protein 1 (pr-1) genes in watermelon (Citrullus lanatus (Thumb.) Matsum. & Nakai)

Watermelon (Citrullus lanatus (Thumb.) Matsum. & Nakai) is an economically significant and popular agricultural crop worldwide. The production of watermelons is subject to limitations imposed by biotic and abiotic factors, which can exert a substantial impact on the yield. Pathogenesis-related (PR) proteins are a class of proteins that play critical roles in the plant defense system against biotic stress factors that limit plant growth and development. In order to develop and select plants resistant to biotic factors, in-silico analysis of PR1 proteins from the PR family was performed in the C. lanatus genome. In the course of the analysis, 19 PR1 genes were identified. The majority of genes that carry a single exon are capable of producing PR1 proteins (CsPR1) with a molecular weight range of 14–25 kDa. The PR1 proteins in question are typically predicted to be water-soluble and located in the extracellular space. The proteins were found to carry the CAP_PR-1 (IPR001283/ Allergen V5/ Tpx-1-related) domain, which has been demonstrated to confer antifungal, antibacterial, and antiviral properties. The proteins were found to contain conserved motifs. The CAP1, CAP2, CAP3, CAP4, and CBM regions of the ClPR1 proteins were identified as being critical in pathogen-protein interactions. The NJ-based phylogeny of ClPR1 proteins revealed the presence of three major groups. The majority of their genes were found to be clustered on chromosome 2, with additional genes located on chromosomes 2, 3, 4, 6, and 10. The 3D structures of the proteins were further generated and analyzed based on the homology of the 1CFE-encoded PR14A (Solanum lycopersicum) protein. In summary, the identification and characterization of PR1 proteins in the watermelon genome was carried out by in-silico method, and the information obtained was presented to the literature to contribute to further molecular breeding studies. Keywords: Biotic factor, plant pathogens, tolerance, molecular response