Expression of Tobacco Lipid Transfer Protein NtLTP4 Enhances Tolerance to Abiotic and Biotic Stresses in Transgenic Potato Lines

Potato (Solanum tuberosum L.) is the world’s most important non-grain food crops, so it is important to improve the potato yield and quality. Lipid transfer proteins (LTPs) play critical roles in various environmental stresses. Here, we studied the function of the heterologous overexpression of NtLTP4 from Nicotiana tabacum in potato. We cloned ubiquitin promoter ubi3 from potato, and then constructed the plant expression recombinant plasmid ubi3:pX6–NtLTP4, and transformed it into potato. PCR results indicated that 15 positive plants were obtained. Furthermore, quantitative real-time PCR data showed that 5 plants had high expression level of NtLTP4 gene. Western blot analyses showed that the NtLTP4 gene and its encoded protein (about 12 kDa) were normally transcribed and expressed in potato, indicating that transgenic NtLTP4 potato plants were successfully obtained. The tolerance to salt, drought, and Ralstonia solanacearum of potato plants with NtLTP4 overexpression was enhanced compared with that of non-transgenic plants. The resistance mechanism was also studied by detecting related resistance and functional genes. This study provides a method to improve potato resistance and obtain new transgenic potato varieties.