Sulfite dynamics affect drought tolerance and water status in Arabidopsis and tomato.

Enhanced sulfite homeostasis through overexpression of SO, SiR, and APR2 reduces water loss and improves drought tolerance in Arabidopsis and tomato, with SO OE plants showing the lowest water loss.

• Why it matters: Understanding how sulfite dynamics influence drought resilience is crucial for developing crops with better water retention, especially under prolonged drought conditions. The role of sulfite in modulating water loss and hormone signaling remains unclear, limiting targeted interventions.
• What they did: The study examined Arabidopsis and tomato plants with altered sulfite homeostasis, including SO overexpression, apr2 knockout, and gene-edited lines, assessing water content, sulfite levels, and hormone signaling under drought stress.
• The result: Plants with enhanced sulfite oxidation and reduction maintained higher relative water content, with SO OE and related lines showing reduced sulfite accumulation, decreased antagonism of ABA signaling, and improved drought resilience across species.