The Positive Regulation of Putrescine on Light-Harvesting Complex II and Excitation Energy Dissipation in Salt-Stressed Cucumber Seedlings

•Put increases heat dissipation capacity of salt stressed cucumber leaves.•Put maintains the stability of the light-harvesting complexs of PSII.•Put can affects the level of translation and transcription of LHCII protein subunits.•Put promotes the transformation of free PAs into conjugated PAs by regulating TGase.