Genome-wide identification and characterization of the plant defensins (Pdfs) gene family in selected Leguminous crops and their expression profiles in response to biotic and abiotic stresses

Abstract

Plant defensins (Pdfs) represent a subset of cationic antimicrobial peptides characterized by a distinct tertiary structure. Similar to their counterparts in insects and mammals, they play a pivotal role in the innate immunity of plants, exhibiting broad-spectrum antifungal activity. This study focused on a comprehensive genome-wide survey to identify Pdfs genes within eight distinct legume crops. This study revealed the presence of Pdfs genes in eight leguminous plants such as 13 in P. sativum, 6 in P. vulgaris, 16 in M. trunculata and 4 in C. cajon, 6 in G. max, 5 in A. hypogea, 5 in C. arietinum, and 4 in V. angularis. Utilizing various bioinformatic analyses including phylogeny, motif, and gene structure analysis, identified Pdfs genes were categorized into two distinct groups i.e., group A (comprising subgroups A1, A2, A3, A4, A5) and group B 2 (B1 and B2). This clustering was based on protein sequences, where the presence of a proline-rich domain at the N-terminal and a linker DNA domain at the C-terminal facilitated differentiation. Gene structural analysis uncovered a variable range of 1 to 3 introns within Pdfs genes. Moreover, promoter analysis highlighted the abundance of cis-regulatory elements upstream of Pdfs genes, responsive to a diverse spectrum of biotic and abiotic stress stimuli. Expression analysis underlined the crucial role of Pdfs protein in defense responses in leguminous plants against both pathogenic and environmental stressors. These findings underscore the involvement of Pdfs in strengthening the defense mechanisms of legumes and provide fundamental insights essential for prospective investigations into Pdfs.