Recently, soil contamination of agricultural land by heavy metals has become a serious problem (Miransari, 2016; Zhang et al., 2018). Cadmium (Cd) is a toxic element for plants. Cd can inhibit plant growth, development, and productivity by disrupting amino acid biosynthesis, inhibiting enzyme activity, interfering with mineral nutrition, and metabolic imbalances (Liu et al., 2015a; Yang et al., 2018). Copper (Cu) is essential as a plant microelement but in excess amounts it becomes highly toxic and inhibits photosynthesis (Dey et al., 2014), nutrient uptake, plant growth (Adrees et al., 2015), and ultimately causes cell death (Printz et al., 2016). In addition, excessive amounts of heavy metals induce oxidative stress, causing an increased formation of reactive oxygen species (ROS)