Identification and biochemical characterization of the glutathione reductase family from Populus trichocarpa

•PtGR genes (PtGR1.1/1.2/2) were expressed in root, stem, leaf, bud, and the expression level was general upregulated under salicylic acid and alamethicin treatments.•PtGR1.1 and PtGR1.2 were localized in cytoplasm, while PtGR2 was in chloroplast.•The three PtGR proteins showed different enzymatic activities, apparent kinetic characteristic and thermal stability profiles. However, they have similar bivalent metal ions (Cu2+, Cd2+, Zn2+ and Pb2+) sensitivity and optimum pH profiles.