Hydrogen peroxide positively regulates ABA signaling via oxidative modification of the C2H2-type zinc finger protein ZFP36 in rice.

The rice zinc finger protein ZFP36 serves as a pivotal regulator of the hydrogen peroxide (H ₂ O ₂ ) signaling pathway in response to abscisic acid (ABA). Its role is crucial for integrating H ₂ O ₂ signals with the plant defense mechanisms against water deficit and oxidative stress. However, it remains unclear whether ZFP36 directly modulates ABA-induced H ₂ O ₂ signaling. This study explored the effects of oxidative post-translational modifications (OxiPTMs) on ZFP36 in rice, with an emphasis on the H ₂ O ₂ -induced oxidation through its cysteine (Cys) residues. We found that ZFP36 undergoes oxidative modification as a target of H ₂ O ₂ in the presence of ABA, specifically at Cys32. Employing quantitative detection and fluorescence assays, we observed that ZFP36 oxidation enhances the expression and activity of genes encoding protective antioxidant enzymes. Moreover, our investigation into the thioredoxin (Trx) and glutaredoxin (Grx) families revealed that OsTrxh1 facilitates the reduction of oxidized ZFP36. Genetic evidence indicates that ZFP36 positively influences rice resilience to oxidative and water stress, while OsTrxh1 exerts an opposing effect. These insights reveal a distinctive pathway for plant cells to perceive ABA-induced H ₂ O ₂ signaling, advance our comprehension of H ₂ O ₂ signaling dynamics, and ABA-related plant responses, and lay a vital groundwork for enhancing crop stress tolerance.
Competing Interests: Declaration of competing interest The authors declare that they have no known financial interests or personal relationships that might influence the work reported in this paper. The authors declare no conflicts of interest.
(Copyright © 2024 Elsevier Masson SAS. All rights reserved.)