Disease resistance in cypress involves a dynamic transcriptome-wide response that includes resistance genes characterized in model pathosystems

Authors: Kasuga, Takao; SCALI, EDOARDO - University Of California Berkeley; DELLA ROCCA, GIANNI - National Research Council - Italy; EMILIANI, GIOVANNI - National Research Council - Italy; DANTI, ROBERTO - National Research Council - Italy; BARBERINI, SARA - National Research Council - Italy; GHELARDINI, LUISA - University Of Florence; GARBELOTTO, MATTEO - University Of California Berkeley

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/13/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cypress Canker Disease is a widespread fungal disease that threatens cypress trees worldwide. Although some cypress trees have been bred to resist the disease, the biological reasons for this resistance were not well understood. In this study, researchers compared disease-resistant and susceptible cypress trees by examining which genes became active after infection. Resistant trees responded earlier and more strongly, activating many defense-related genes over time, while susceptible trees showed a weaker response. For the first time, several known plant disease-resistance genes were identified in cypress trees. The results show that resistance is not due to a single gene, but to multiple defense systems working together, including stress responses and immune signaling. These findings help explain how some cypress trees survive infection and may help breeders and forest managers identify and select more disease-resistant trees in the future.

Technical Abstract: Cypress Canker Disease (CCD) is a tree pandemic caused by fungi in the genus Seiridium. Cupressaceae plants, including Cupressus sempervirens, are the main hosts of CCD. Although breeding programs have identified CCD-resistant C. sempervirens clones, molecular mechanisms conferring resistance remain unknown. Here, we present the first transcriptomic analyses of the S.cardinale-C.sempervirens pathosystem using a dual RNA-seq approach across resistant and susceptible clones at 3, 15, and 30 days post fungus inoculation. An early and sustained transcriptional activation was observed in resistant clones, characterized by higher numbers of differentially expressed genes than in susceptible plants. Notably, resistance genes such as Roq1, RUN1, TAO1 and RPV1 were observed in Cupressus for the first time. These genes, together with stress-related genes and transporters, were upregulated in resistant clones. Host clonality facilitated the identification of gene variants uniquely associated with resistance and of gene subsets whose temporal expression patterns suggest dynamic roles during disease progression. Differential expression between wounded and fungus-inoculated tissues allowed us to disentangle responses linked to wounding from those specific to infection. Our findings demonstrate that CCD resistance in cypress is quantitative and integrates stress responses, signaling, and R-genes. These genes may be biomarkers of resistance in cypress populations.