GmCRF1‐like2 Positively Regulates Resistance to Phytophthora sojae Through XTH ‐Mediated Cell Wall Remodeling

Phytophthora root rot, caused by Phytophthora sojae , poses a significant threat to soybean ( Glycine max ) production worldwide. APETALA2/ethylene responsive factor (AP2/ERF) transcription factors play crucial roles in plant immune regulation, but the functions of subfamily cytokinin response factor (CRF) in soybean disease resistance remain largely unexplored. In this study, expression analysis revealed that GmCRF1‐like2 was significantly induced by P. sojae infection, which showed notably higher expression levels in the resistant variety Suinong 10 compared with the susceptible variety Dongnong 50. Agrobacterium rhizogenes ‐mediated hairy root transformation indicated that overexpression of GmCRF1‐like2 significantly enhanced resistance to P. sojae , whereas RNA interference‐mediated silencing increased disease susceptibility in soybean. Transcriptomic analyses of overexpression lines identified 6892 differentially expressed genes, and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis revealed significant enrichment in “phenylpropanoid biosynthesis” and “plant‐pathogen interaction” pathways. Importantly, four xyloglucan endotransglucosylase/hydrolase ( XTH ) family genes including GmXTH31 , GmXTH34 , GmXTH44 , and GmXTH49 were significantly upregulated. RT‐qPCR validation confirmed that GmCRF1‐like2 positively regulates the expression of these XTH genes, which could involve cell wall remodeling through xyloglucan modification in response to P. sojae . Therefore, we proposed that GmCRF1‐like2 mediated soybean defense against P. sojae by transcriptionally activating the XTH gene family, triggering cell wall remodeling, and enhancing plant resistance. This study suggests a potential molecular mechanism by which CRF transcription factors regulate plant disease resistance through cell wall modification, offering potential targets for improving soybean disease resistance.