To better understand the mechanisms of Se tolerance in Cardamine enshiensis, the authors constructed the 443Mb genome for C. enshiensis and performed RNA-seq and Widely-Targeted Metabolomics on seedlings treated with water (control) or 400uM sodium selenite.

Mechanisms of Se tolerance and hyperaccumulation in C. enshiensis

In total, 29,671 differentially expressed genes were identified and a total of 558 metabolites were identified in the leaf tissue of C. enshiensis, of which 127 were differential metabolites. The authors found 10 flavone-related metabolites were altered between the two groups, indicating that flavones play a pivotal role in Se tolerance. KEGG analyses showed the significantly enriched pathways were associated with the biosynthesis of secondary metabolites and flavone/flavonoid/flavonol compounds. A Pearson’s correlation coefficient threshold of r > 0.8 was used to identify the metabolites that were significantly correlated with each gene and the results revealed that 175 transcripts were highly correlated (R2 > 0.96) with tricetin O-malonylhexoside and amentoflavone.

ETHYLENE INSENSITIVE 3-LIKE 2 regulates β-carotene and ascorbic acid in tomatoes during ripening