Transcriptomic and metabolomic analysis uncover core salt-responsive elements in Hordeum marinum

Area of Science:

• Plant Biology
• Genomics
• Biochemistry

Background:

• Sea barley (Hordeum marinum) is a wild relative known for superior salt tolerance.
• Salt tolerance mechanisms vary among sea barley accessions and require further characterization.
• Previous work included de novo genome assembly of sea barley accession H559.

Purpose of the Study:

• To compare transcriptomic and metabolomic responses to salt stress in two sea barley accessions with differing salt tolerance.
• To identify key genes and metabolites involved in salt tolerance in sea barley.
• To provide insights for improving salt tolerance in crops.

Main Methods:

• Comparative transcriptomic (RNA-seq) and metabolomic (LC-MS) analyses were performed on salt-stressed sea barley accessions.
• Two accessions, salt-tolerant H512 and salt-sensitive H111, were subjected to 300 mM NaCl for 14 days.
• Differential gene expression (DEGs) and metabolite levels (DEMs) were analyzed.

Main Results:

• Salt-tolerant H512 exhibited greater biomass accumulation and higher shoot K+/Na+ ratio compared to H111.
• Significant differences in gene expression related to ion transporters, Ca2+ signaling, and transcription factors were observed between accessions.
• H512 showed energy-saving strategies by modulating ATP synthesis/hydrolysis gene expression and enhanced antioxidant activity via specific metabolites.

Conclusions:

• Key candidate genes and metabolites governing ion homeostasis, oxidative defense, and energy metabolism were identified in sea barley.
• Differential multi-omics responses highlight distinct strategies for salt tolerance in H512.
• Findings offer valuable insights for genetic improvement of salt tolerance in agricultural crops.