Genomic identification of the NAC gene family and its expression pattern in responding to salt stress in Taxodium distichum

The NAC transcription factor family plays a fundamental role in plant growth, development, and responses to various stresses. However, systematic characterization of the NAC gene family in Taxodium distichum and its potential roles in salt-stress responses remain largely unexplored. In this research, we identified 55 TdNAC genes via a genome-wide analysis of T. distichum . Phylogenetic analysis classified these genes into 17 subfamilies, and the majority of TdNAC proteins were predicted to localize to the nucleus. Conserved motif analysis revealed structural conservation among TdNAC proteins, while promoter analysis identified numerous stress- and hormone-responsive cis-elements. The tissue-specific expression patterns indicated the functional diversification of these genes, and salt stress treatment induced dynamic, tissue-specific expression alterations. Transient expression of TdNAC38 in T. distichum callus resulted in enhanced antioxidant enzyme activities and reduced malondialdehyde (MDA) accumulation under salt stress, suggesting that it could participate in regulating salt-stress responses. These findings provide a basis for the functional exploration of TdNAC38 and offer a potential molecular breeding strategy for improving salt tolerance in T. distichum .