Figure 2.
Schematic model of the interaction among H2, H2S, NO, CO, and CH4 in different abiotic stress processes: (a) The interaction of H2 and NO increased antioxidant defenses in stressed plants. (b) Involvement of HO-1 in H2 induced different environment stress tolerances in plants. (c) The crosstalk between H2S and NO upregulated the ASA-GSH cycle, which enhanced the activity of some antioxidant enzymes and alleviated the damage of abiotic stresses to plants. (d) CO enhanced abiotic stress tolerance via NO-mediated maintenance of ion balance and the upregulation of antioxidant defense in plants.