Root endophyte sulfur metabolites enhance redox balance and drought tolerance in Arabidopsis.

Pseudomonas argentinensis SA190 enhances sulfate uptake and increases the shoot GSH/GSSG ratio in PEG-induced drought-stressed Arabidopsis, strengthening redox resilience.

• Why it matters: Drought limits crop productivity, and while SA190 improves plant performance, the sulfur- and redox-based mechanism behind its benefits was unclear.
• What they did: Arabidopsis sulfur-related mutants were tested under PEG-induced drought, and SA190 effects were assessed via sulfate uptake and glutathione redox changes; GSH biosynthesis was inhibited with buthionine sulfoximine (BSO).
• The result: SA190 elevates GSH under PEG stress, and blocking GSH biosynthesis with BSO supports SA190’s contribution; bacterial GSH or its precursor γ-glutamylcysteine (γ-EC) is implicated in improved growth.