Hormonal regulation and cell wall‐degrading enzymes: dual strategies of Fusarium solani in passion fruit stem rot pathogenesis

BACKGROUND: Stem rot caused by Fusarium solani significantly threatens passion fruit production. However, the pathogenic mechanisms and host defenses remain unclear. We investigated hormonal dynamics, gene regulatory networks, and pathogenic factors during F. solani infection among resistant and susceptible passion fruit cultivars. RESULTS: The susceptible cultivar exhibited significantly higher levels of auxin (indole-3-acetic acid, IAA), salicylic acid (SA), jasmonic acid (JA), and abscisic acid (ABA), accompanied by up-regulated expression of auxin biosynthesis (AMI1, AAO1) genes. The pink module in the weighted gene co-expression network analysis correlated strongly with JA, SA, ABA, and tryptophan; hub genes included IAA-amido synthetase and WRKY transcription factors. Enrichment of cell wall-degrading enzymes strongly correlated with SA, JA, ABA and tryptophan levels. Hence, F. solani may manipulate host hormone signaling and secrete pectin lyases to facilitate infection. CONCLUSION: This study provides insights into hormone-pathogen interactions, informing strategies for breeding disease-resistant passion fruit and developing environmentally friendly control measures. © 2026 Society of Chemical Industry.