The wheat NAC transcription factor TaNAC22 enhances cadmium stress tolerance in wheat

Cadmium (Cd) pollution is a main problem in food production as it reduces crop yield and threatens human health. However, the pathway of Cd accumulation in plants is still unclear. In this investigation, we report that TaNAC22, a novel NAC transcription factor, is involved in Cd tolerance in wheat. TaNAC22 cDNA includes an open reading frame of 909 bp encoding 302 amino acids. The qRT-PCR analysis showed that TaNAC22 was expressed at the peak level in the leaves and sufficiently induced under Cd stress. Subcellular localization analysis in onion epidermal cells indicated that TaNAC22 protein was localized to the nucleus. Expression of TaNAC22 in wheat plants conferred Cd tolerance and transgenic wheat exhibited a higher soluble sugar, proline and superoxide dismutase, peroxidase and catalase content, but lower contents of malondialdehyde, H2O2 and O2−. In addition, the expression of Cd-responsive genes in transgenic wheat was lower than that in WT lines under Cd stress. In summary, our data suggested that TaNAC22 was closely related to Cd tolerance, providing a basis for in-depth study on the Cd tolerance molecular mechanism of TaNAC22 in wheat.