Related Experiment Video
Updated: Sep 9, 2025
CcCIPK14 Gene Function Analysis to Illuminate the Efficient Root Transgenic System
Published on: September 23, 2021
PDF gene family in four Cucurbitaceae species: genome-wide identification, classification and expression in response
Ba Dun1,2,3, Sun Chengzhen1,2,3, Ding Zhuo1,2,3
1College of Horticulture Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, 066000, China.
Background:
Plant defensins (PDF) represent a crucial superfamily of innate immune proteins that exhibit antifungal and antibacterial activities, significantly contributing to biotic stress. Despite being significant horticultural and economic crops, a comprehensive genome-wide analysis of Cucurbitaceae plant defensin genes (CuPDF) remains unreported.
Results:
In this study, 19 CuPDF family members homologous to Arabidopsis PDF were predicted in four Cucurbitaceae and validated based on the presence of conserved PDF-related domains. The 19 CuPDF are unevenly distributed across the chromosomes, and phylogenetic analysis reveals their classification into two distinct subgroups, consistent with those identified in Arabidopsis thaliana. The similarity in 3D protein structures, together with the conserved intron-exon organization and core motif distribution, collectively indicates strong evolutionary conservation. Synteny analysis suggests that the expansion of the CuPDF family in cucurbits is predominantly driven by tandem duplication events. Promoter analysis revealed that the upstream regions of CuPDF are enriched with numerous cis-acting elements associated with plant hormone signaling, defense responses, stress responses, and developmental regulation, including MYB (59 elements), MYC (58), ARE (37), ABRE (40), ERE (40), and AAGAA-motif (36). RNA-seq analysis showed that the expression levels of CmPDF9, ClPDF1.1/1.2/2, and CmoPDF20 were differentially upregulated or downregulated in response to various biotic stresses, including Phytophthora capsici, Fusarium oxysporum, Pseudoperonospora cubensis, Podosphaera xanthii, cucumber green mottle mosaic virus (CGMMV), and Meloidogyne incognita. These findings suggest that these genes may play regulatory roles in biotic stress responses, as further confirmed by RT-qPCR.
Conclusions:
In this study, the structure, chromosomal distribution, and evolutionary relationship of PDF family members in four Cucurbitaceae were analyzed. We identified the CuPDF genes involved in biotic stress by combining promoter element analysis, transcriptome data, and RT-qPCR analysis. These findings enrich the knowledge of the molecular characteristics of the CuPDF family and provide crucial insights into their potential roles in responses to biotic stress.
