Comprehensive Identification and Integrated Analysis of the PR1 and PR10 Gene Families in Ginseng: PgPR1-5 and PgPR10-8 Gene Expression Analysis in Response to MeJA.

Pathogenesis-related (PR) proteins are central to plant defense; however, their roles in regulating secondary metabolism remain largely unexplored. In Panax ginseng, the molecular characteristics and functional links of PR1 and PR10 gene families to ginsenoside biosynthesis remain unclear. Here, we conducted genome and transcriptome identification, evolutionary analysis, co-expression network construction, and methyl jasmonate (MeJA) induction assays to investigate their roles. We identified 34 PR1/PR10 family members (11 PgPR1s and 23 PgPR10s) unevenly distributed across 15 chromosomes, with gene duplication driving family expansion. Functional divergence was evident: PgPR1 members are evolutionarily conserved and root-preferential, associated with antibacterial defense, whereas PgPR10 underwent species-specific expansion, showed broad tissue expression, and possessed promoters enriched with hormone- and stress-responsive cis-elements. Co-expression analysis (|r| ≥ 0.3, p < 0.001) identified PgPR1-5 and PgPR10-8 as the only PR members significantly correlated with key ginsenoside biosynthetic enzymes. Under MeJA, the ginsenoside pathway displayed bidirectional temporal regulation, with core PR genes showing synchronized expression with the negatively regulated enzyme gene CAS_14. Our study characterizes the molecular and evolutionary features of PgPR1/PgPR10 families, identifies core PR genes associated with ginsenoside metabolism, and reveals their coordinated response to MeJA, providing key insights and candidate targets for exploring the potential link between PR proteins and ginsenoside biosynthesis and promising candidate genes for further research on P. ginseng.