SlMYBS3L-SlERF.E4-SlGGP1 mediates the accumulation of ascorbic acid in tomato promoted by organic nutrient solution.

Organic nutrient solution treatment significantly boosts ascorbic acid content in tomato fruits by activating the SlERF.E4–SlGGP1 module, with SlERF.E4 directly binding the SlGGP1 promoter.

• Why it matters: Organic cultivation enhances fruit ascorbic acid, but the molecular mechanism linking organic nutrient signaling to ascorbic acid biosynthesis is poorly understood.
• What they did: The study identifies SlERF.E4 as a positive regulator of OR-induced ascorbic acid biosynthesis that directly binds the DRE motif in the SlGGP1 promoter and activates SlGGP1 transcription; it also finds SlMYBS3L suppresses SlERF.E4 and inhibits SlGGP1 under inorganic conditions.
• The result: OR treatment downregulates SlMYBS3L, releasing inhibition on SlERF.E4 and SlGGP1, thereby synchronously activating the SlERF.E4–SlGGP1 module and enhancing ascorbic acid biosynthesis in tomato.