Hydrogen sulfide alleviates the cold stress through MPK4 in Arabidopsis thaliana

Abstract Hydrogen sulfide (H 2 S) is a gaseous signaling molecule that mediates physiological processes in animals and plants. In this study, we investigated the relationship of H 2 S and mitogen activated protein kinase (MAPK) under cold stress in Arabidopsis. H 2 S up-regulated MAPK expression levels and was involved in the cold stress-related upregulation of MAPK genes expression. We then chose MPK4 whose expression level was influenced the most by H 2 S as a target and found that H 2 S's ability to alleviate cold stress required MPK4. Both H 2 S and MPK4 regulated the expression levels of the cold response genes inducer of CBF expression 1 ( ICE1 ), C-repeat-binding factors ( CBF3 ), cold responsive 15A ( COR15A ) and cold responsive 15B ( COR15B ). H 2 S inhibited the opening of stomata under cold stress, which required the participation of MPK4. In conclusion, MPK4 is a downstream component of H 2 S-related cold-stress resistance, and H 2 S and MPK4 both regulated the cold response genes and stomatal movement to response the cold stress.