Comprehensive transcriptional analysis unveils salt stress-regulated key pathways in Suaeda salsa leaves

Suaeda salsa represents a promising halophyte model for investigating the mechanisms underlying salt tolerance in plants. However, the molecular mechanisms regulating seedling establishment of Suaeda salsa remain unknown. Thus, the current study was conducted to understand the underlying regulatory mechanisms in Suaeda salsa leaves exposed to 0 mM, 200 mM, 400 mM, and 800 mM NaCl using high-throughput RNA sequencing. The number of differentially expressed transcripts substantially increased when the salinity level elevated, suggesting major transcriptional reorganization in response to salinity stress. Importantly, the differentially identified transcripts were mostly salt responsive genes belonging to specific categories like plant hormone signaling, solute transport and nutrient uptake, protein metabolism, and transcriptional regulation. Specifically, higher level of salt changed 339 genes markedly implicated in transcriptional regulation such as MYB, MADS-box, NAC, ERF, WRKY, HB families, as well as genes involved in protein metabolism such as the tyrosine-like protein and ATG members and autophagic cargo receptor protein. This indicated important key players to high salt tolerance. Collectively, our findings revealed the crucial regulatory pathways underlying the salt tolerance of Suaeda salsa through a cascade that includes signal perception and transduction, and transcription factors that regulate the downstream response genes such as those involved in protein metabolism, solute and nutrient transport for salt stress adaptation.