Overexpression of Populus euphratica xyloglucan endotransglucosylase/hydrolase gene confers enhanced cadmium tolerance by the restriction of root cadmium uptake in transgenic tobacco

•Populus euphratica XTH confers cadmium tolerance in tobacco.•PeXTH-transgenic tobacco reduces Cd2+ accumulation within root cells.•Tobacco plants overexpressing PeXTH reduces Cd2+ influx along roots.•PeXTH overexpression increases the degradation of xyloglucan in the cell wall.•The declined xyloglucan leads to less binding sites for Cd2+ in transgenic tobacco.