The molecular framework underlying the growth and defense tradeoff in Arabidopsis roots in response to danger signals

Elevated stress signaling often compromises plant growth by suppressing proliferative and formative divisions at the meristem. Plant Elicitor Peptide 1 (PEP1), an endogenous danger signal triggered by both biotic and abiotic stresses in Arabidopsis thaliana, suppresses proliferative divisions, alters xylem vessel organizations, and disrupts cell-to-cell symplastic connections in the root. To gain an insight into the dynamic molecular framework that modulates root development under elevated danger signals, we performed a time course RNA-sequencing analysis at the root meristem following PEP1 treatment. A series of data analyses revealed that STZ and its homologs are a potential nexus between the stress response and proliferative cell cycle regulation. We observed that STZ differentially controls the cell cycle, cell differentiation, and stress response genes at various tissue layers in the root meristem through various functional, phenotypic, and transcriptomic analyses. Our study further indicated that the expression level of STZ in response to stresses is critically important to enable the growth and defense tradeoff. The findings here provide valuable information about the dynamic gene expression changes upon perceiving danger signals at the root meristem and future engineering schemes to generate stress-resilient plants.