Oil Palm AP2 Subfamily Gene Improves Salt Stress Tolerance in Transgenic Tobacco Plants.

AP2/ERF transcription factor genes play an important role in regulating the responses of plants to various abiotic stresses, such as cold, drought, high salinity, and high temperature. However, less is known about the function of oil palm AP2/ERF genes. We previously obtained 172 AP2/ERF genes of oil palm and found that the expression of was significantly up-regulated under salinity, cold, or drought stress conditions. In the present study, the sequence characterization and expression analysis for were conducted, showing that it was transiently over-expressed in L. The results indicated that transgenic tobacco plants over-expressing could have a stronger tolerance to salinity stress than wild-type tobacco plants. Compared with wild-type plants, the over-expression lines showed a significantly higher germination rate, better plant growth, and less chlorophyll damage. In addition, the improved salinity tolerance of transgenic plants was mainly attributed to higher antioxidant enzyme activities, increased proline and soluble sugar content, reduced HO production, and lower MDA accumulation. Furthermore, several stress-related marker genes, including , , , , , , and , were significantly up-regulated in transgenic tobacco plants subjected to salinity stress. Overall, over-expression of the gene significantly enhanced salinity stress tolerance in transgenic tobacco plants. This study lays a foundation for further exploration of the regulatory mechanism of the gene in conferring salinity tolerance in oil palm.