Genome-Wide Identification and Expression Analysis of Salt-Tolerance-Associated NAC Family Genes in Cyclocarya paliurus

Abstract

Soil salinity affects approximately 20% of the world’s arable land, presenting a significant challenge for studying the mechanisms by which plants adapt to saline environments. Cyclocarya paliurus, an invaluable research model due to its ecological and medicinal significance, is primarily concentrated in central and southern China. Nevertheless, Cyclocarya paliurus faces challenges from environmental factors such as soil salinization, which adversely impacts its growth, subsequently affecting the yield and quality of its bioactive compounds. The NAC gene family, a critical group of plant-specific transcription factors, plays pivotal roles in responding to abiotic stresses. However, there has not yet been any studies on NAC genes under salt stress in Cyclocarya paliurus. In this study, we identified 132 NAC genes within the Cyclocarya paliurus genome. Our analysis of the conserved structures and gene organization revealed a high degree of conservation in the proteins of the CpNAC gene family. Cis-element analysis unveiled the participation of these genes in a variety of biological processes, including light responses, phytohormone responses, cell cycle responses, and abiotic stress responses. Under salt stress conditions, the expression of 35 CpNAC genes changed significantly, indicating a response to salt treatment. Furthermore, we provided additional evidence for the identification of the NAC gene family and revealed their potential positive regulatory role in signal transduction by conducting a transcriptional activation activity analysis of CpNAC132(D) and CpNAC040, which are homologous to Arabidopsis thaliana NAC062/91 and NAC103, respectively. This research not only advances our comprehension of the salt stress adaptation in Cyclocarya paliurus but also provides robust support for future investigations into plant responses to environmental stress and the cultivation of salt-tolerant crops.