Proteome sequencing identifies key salt-tolerant proteins in poplar and PsnLEA4-5 enhances poplar salt tolerance

Poplar is a significant species in silviculture; however, its natural growth may be constrained by salt stress. In this paper, we conducted an investigation into the proteins present in poplar leaves as a response to salt stress, and we analyzed the alterations in protein and gene expression following salt stress through the application of proteomic and transcriptomic sequencing technologies. Differential expression analysis identified 149 significantly differentially accumulated proteins (DAPs), which mainly involved biological processes and pathways such as photosynthesis, amino acid metabolism, glutathione metabolism and oxidative phosphorylation. Weighted gene co-expression network analysis revealed 20 crucial proteins that exhibited significant correlations with the duration of salt stress, the majority of which were associated with biological processes pertaining to plant stress tolerance. In addition, we overexpressed the hub protein PsnLEA4-5 in 84K poplar and found that this gene significantly enhanced the salt tolerance of poplar, contributed to ionic homeostasis and enhanced ROS scavenging capacity. This work provides an important reference for tree stress research and resistance breeding.