Salicylic acid (SA) can induce plant resistance to biotic and abiotic stresses through cross talk with other signaling molecules, whereas the interaction between hydrogen peroxide (H 2 O 2 ) and abscisic acid (ABA) in response to SA signal is far from clear. Here, we focused on the roles and interactions of H 2 O 2 and ABA in SA-induced freezing tolerance in wheat plants. Exogenous SA pretreatment significantly induced freezing tolerance of wheat via maintaining relatively higher dark-adapted maximum photosystem II quantum yield, electron transport rates, less cell membrane damage. Exogenous SA induced the accumulation of endogenous H 2 O 2 and ABA. Endogenous H 2 O 2 accumulation in the apoplast was triggered by both cell wall peroxidase and membrane-linked NADPH oxidase. The pharmacological study indicated that pretreatment with dimethylthiourea (H 2 O 2 scavenger) completely abolished SA-induced freezing tolerance and ABA synthesis, while pretreatment with fluridone (ABA biosynthesis inhibitor) reduced H 2 O 2 accumulation by inhibiting NADPH oxidase encoding genes expression and partially counteracted SA-induced freezing tolerance. These findings demonstrate that endogenous H 2 O 2 and ABA signaling may form a positive feedback loop to mediate SA-induced freezing tolerance in wheat.
Wang, W., Wang, X., Huang, M., Cai, J., Zhou, Q., Dai, T., … Jiang, D. (2018). Hydrogen peroxide and abscisic acid mediate salicylic acid-induced freezing tolerance in wheat. Frontiers in Plant Science, 9. https://doi.org/10.3389/fpls.2018.01137