Hydrogen Sulfide–Phytohormone Interaction in Plants Under Physiological and Stress Conditions

Hydrogen sulfide (H2S), as a novel gaseous signalling molecule, has been extensively investigated in plants ranging from seed germination to senescence. Phytohormones, including stimulator (such as auxin: AUX; gibberellin: GA; cytokinin: CTK; and melatonin: MEL) and inhibitor (such as ethylene: ETH; abscisic acid: ABA; salicylic acid: SA; and jasmonic acid: JA) types, as universal regulators, play a key role in the plant growth, development, and response and adaptation to adverse environments. Now, phytohormones are considered to be the key targets for improving plant productivity and stress tolerance, which affect the production and quality of crop plants. These indicate the interaction of H2S with phytohormones in many physiological processes such as seed germination, seedling establishment, plant growth, development, and senescence, as well as response to environmental stress. However, the molecular mechanism of H2S–phytohormone interaction is not completely clear. In this review, the interaction of H2S with stimulator hormones (AUX, GA, and MEL) and inhibitor hormones (ETH, ABA, SA, and JA) in plants under physiological and stress conditions was discussed. The H2S–phytohormone interaction not only highlighted H2S-mediated phytohormone signaling in stomatal development and closure, fruit ripening, organ abscission, as well as heat, chilling, salt, cadmium, iron deficiency, and boron tolerance; but also focused on the phytohormone-mediated H2S signaling in seed germination, root development, stomatal closure, fruit ripening, organ abscission, as well as drought, chilling, and cadmium tolerance. The aim is to arouse the rapid development of the research on H2S, phytohormones, and their interaction in plant biology field, laying the foundation of acquiring transgenic crop plants with high yield, high quality, and multiple stress tolerance.