Single-cell profiling of Arabidopsis leaves to Pseudomonas syringae infection

Plant response to pathogen infection varies within a leaf, yet this heterogeneity is not well resolved. We expose Arabidopsis to Pseudomonas syringae or mock treatment and profile >11,000 individual cells using single-cell RNA sequencing. Integrative analysis of cell populations from both treatments identifies distinct pathogen-responsive cell clusters exhibiting transcriptional responses ranging from immunity to susceptibility. Pseudotime analyses through pathogen infection reveals a continuum of disease progression from an immune to a susceptible state. Confocal imaging of promoter-reporter lines for transcripts enriched in immune cell clusters shows expression surrounding substomatal cavities colonized or in close proximity to bacterial colonies, suggesting that cells within immune clusters represent sites of early pathogen invasion. Susceptibility clusters exhibit more general localization and are highly induced at later stages of infection. Overall, our work shows cellular heterogeneity within an infected leaf and provides insight into plant differential response to infection at a single-cell level.

Automated summary

In this study, the researchers used single-cell RNA sequencing to analyze the cellular response of Arabidopsis to Pseudomonas syringae infection. They identified distinct cell clusters with different transcriptional responses, ranging from immunity to susceptibility. Confocal imaging revealed that cells within immune clusters were sites of early pathogen invasion, while susceptibility clusters showed a more general distribution and were induced at later stages of infection. This study provides insights into the cellular heterogeneity and differential response of plants to infection at the single-cell level.