Enhances the Tolerance to Aluminum Stress in .

Aluminum (Al) toxicity causes severe reduction in crop yields in acidic soil. The natural resistance-associated macrophage proteins (NRAMPs) play an important role in the transport of mineral elements in plants. Recently, and were reported specifically to transport trivalent Al ions. In this study, we functionally characterized , a gene previously identified from RNA-Seq data from Al-treated maize roots, in response to Al exposure in maize. was predominantly expressed in root tips and was specifically induced by Al stress. Yeast cells expressing were hypersensitive to Al, which was associated with Al accumulation in yeast. Furthermore, overexpression of in conferred transgenic plants with a significant increase in Al tolerance. However, expression of , either in yeast or in , had no effect on the response to cadmium stress. Taken together, these results underlined an internal tolerance mechanism involving to enhance Al tolerance via cytoplasmic sequestration of Al in maize.