Molecular Mechanisms of Trichosanthes kirilowii in Response to Root-Knot Nematode Infection

Root-knot nematode (RKN) infection poses a serious threat to the yield and quality of the perennial medicinal plant Trichosanthes kirilowii (T. kirilowii) in cultivation. However, its response mechanisms remain unclear. This study analyzed root growth and transcriptomic data at various root-knot nematode infection time points (0, 3, 6, 12, and 24 days post-infection, dpi) for T. kirilowii to reveal its specific response mechanisms. The results showed that RKN infection significantly affected the root growth and gene expression of T. kirilowii. At 24 dpi, individual plants formed an average of 69 galls, indicating the plant shows susceptibility. A total of 14,243 differentially expressed genes (DEGs) were identified, including 382 transcription factors. Weighted gene co-expression network analysis (WGCNA) of DEGs identified four key modules closely associated with RKN infection. GO and KEGG enrichment analyses indicated multiple metabolic pathways involved in the response process, including defense responses, hormone signaling, phenylpropanoid biosynthesis, and MAPK signaling pathways. Hub gene analysis of key modules identified 33 hub genes, including three critical transcription factors. This study demonstrates that T. kirilowii responds to RKN infection through coordinated regulation of multiple metabolic pathways and transcriptional regulatory networks. These findings enhance understanding of the molecular mechanisms underlying T. kirilowii-RKN interactions and provide critical insights for further research on resistance mechanisms and the identification of resistance genes in T. kirilowii.