Exogenous hydrogen peroxide induces chilling tolerance in Phalaenopsis seedlings through glutathione-related antioxidant system

•Chilling injury were occurred in Phalaenopsis amabilis seedlings grown at ≤ 6°C. 50mM H2O2 pretreatment induced chilling tolerance and protective efficiency was strengthened by increased applying frequency, concentration ≥ 100 mM resulted in abnormal leaf morphology.•Chilled seedling with 50 mM H2O2 pretreatment had better membrane thermostability, fewer oxidative stress, higher CO2 assimilation rate also photosystem II efficiency compared with un-treatment.•Exogenous H2O2 pretreatment resulted in an initial minor endogenous H2O2 content increase as signal for chilling acclimated responses. Then, significant elevating GR activity and GSH:GSSG ratio were demonstrated that H2O2-induced chilling tolerance might be mediated by glutathione-related antioxidant system.