CaNAC014 transcription factor enhances salt stress tolerance in pepper by regulating the activity of the CaSOS1 promoter

Pepper is an important vegetable widely grown in the world, and most of them are very sensitive to salt stress. In previous study, CaNAC014 gene responded to NaCl stress. However, the molecular mechanism remains unclear. Therefore, in this study, the overexpression vector pRI101-ANCaNAC014-EGFP and VIGS (virus-induced gene silencing) vector pTRV2-CaNAC014 were transferred into leaves of ‘FJNY-1′ and ‘FJYM-1’ by an Agrobacterium-mediated method. Then these transiently transformed pepper plants were treated with 150 mM NaCl. The results showed that overexpression of CaNAC014 increased salt tolerance in pepper, promoted the plant growth and root development, and maintained significantly higher chlorophyll levels and photosynthetic performance under salt stress, while the silent plants exhibited opposite results. Subcellular localization showed that CaNAC014 was located in the nucleus. A yeast one-hybrid and dual-luciferase assay demonstrated that CaNAC014 could bind to the CaSOS1 promoter. These findings highlight CaNAC014 as a pivotal transcriptional regulator in pepper salt tolerance and provide insights into potential mechanisms of salt stress adaptation in pepper.