Heterologous expression of Solanum tuberosum NAC1 gene confers enhanced tolerance to salt stress in transgenic Nicotiana benthamiana

The plant-specific transcription factors NACs (NAM, ATAF1, 2, CUC), one major transcription factor family, play significant roles in various physiological processes including abiotic stresses. In our study, an NAC gene from potato (Solanum tuberosum L.) was cloned and named as StNAC1 for a high-sequence similarity to SlNAC1, a well-known tomato NAC gene regulating multiple stress responses and fruit ripening. StNAC1 gene was significantly induced under salt stress. Then, we constructed StNAC1-overexpressing transgenic Nicotiana benthamiana plants and obtained three homozygous transgenic lines. The phenotypic analysis results showed that StNAC1-overexpressing transgenic plants had not only higher seed germination and green leaf rates, but also accumulated less ROS and more proline than wide-type plants under salt stress, which resulted in improving transgenic plants salt tolerance. These suggested that StNAC1 gene might function as a positive regulator in plant response to salt stress.