High-throughput screening and structure-guided design of small molecules enable modulation of SAL-PAP stress signaling.

Small molecule V20 inhibits SAL phosphatase activity, increasing PAP levels and stress tolerance in Arabidopsis thaliana with 3-fold greater potency than existing inhibitors.

• Why it matters: Understanding and controlling chloroplast-to-nucleus signaling pathways is crucial for improving plant stress resilience without adverse growth effects.
• What they did: Researchers screened 13,000 compounds, identified V20 as a potent SAL1 inhibitor, and used structural and biochemical analyses alongside molecular dynamics simulations to elucidate its binding mechanism.
• The result: Applying V20 elevated PAP and stress-responsive gene expression, enhancing oxidative tolerance, and demonstrating a new approach to modulate plant stress signaling pathways selectively.