However, zinc deficiency led to an expansion to additional cell layers for ZIP1 promoter (in the stele), ZIP4 promoter (in the stele, cortex and epidermis), ZIP9 promoter (in the cortex and epidermis) and IRT3 promoter (in the stele, cortex and epidermis), similarly to previous observations [30]. Here, SLC39A9 is linked to Zinc deficiency.