Slow-releasing hydrogen sulfide donors for enhancing crop salt tolerance

Overview

Hydrogen sulfide (H2S) is increasingly recognized as an important signaling molecule in plants, influencing growth, development, and stress responses. However, conventional H2S donors such as sodium bisulfide (NaHS) release H2S rapidly, causing shock effects and toxicity that limit their practical use. This research program investigates next-generation, slow-releasing H2S donor compounds—including GYY4137, AP39, and AP67—that release H2S gradually and, in some cases, target specific cellular compartments such as mitochondria. The goal is to characterize how these compounds improve plant growth and salinity tolerance at the biochemical and molecular levels, ultimately enabling their use as agricultural biostimulants.

Technical specifications

Approach and key findings:

• Compounds evaluated: GYY4137, AP39, AP67, with NaHS used as a conventional comparator
• Model system: rice (Oryza sativa), a globally important staple crop sensitive to salinity
• Experimental design: seed pretreatment (2 days) and hydroponic co-application (7 days) at 0–1000 µM doses, followed by salt-stress trials at 100 and 200 mM NaCl for 5 days
• Observations: GYY4137 and AP39 produced dose-dependent increases in root and shoot growth, while NaHS caused growth inhibition and biomass loss
• Salt-stress performance: GYY4137 and AP39 outperformed NaHS in protecting rice plants under saline conditions
• Future work targets the mechanistic basis of action, including interactions with other signaling molecules under stress

Technology readiness level

The program is at an early to mid-stage research and development phase. Preliminary proof-of-concept data have been generated across five independent experiments demonstrating growth promotion and salt-tolerance benefits in rice. Compounds were supplied through a collaboration with Prof. Matt Whiteman at the University of Exeter. A proposed one-year collaboration with Valent Biosciences aims to extend findings to additional crops and advance toward field trials under real-world environmental conditions. The work is positioned between laboratory validation (TRL 3–4) and applied field evaluation, with additional mechanistic and multi-crop studies required before commercial deployment.