Transcriptome analysis of Elymus breviaristatus ‘Tongde’ under different nitrogen treatments

Abstract

Elymus breviaristatus ‘Tongde’ is used for establishing artificial grasslands and is important for maintaining the balanced grassland ecosystem and for soil water conservation on the Qinghai–Tibet Plateau, China. Nitrogen (N) is an important element that affects Tongde development. Thus, we investigated the rational application of N and the molecular mechanism involved. Transcriptome analysis (RNA‐Seq) was conducted using Tongde leaf and root samples produced under controlled conditions with different NH4NO3 treatments (0, 40, 80, and 160 mg L–1). Differentially expressed genes (DEGs) were determined in the leaf and root tissues (0/40 vs. 80/160 mg L–1). We identified 109 DEGs in the leaf samples with 41 upregulated and 68 downregulated genes and 325 DEGs in the root samples with 71 upregulated and 252 downregulated genes. Analysis based on Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathways indicated that members of the LOX and ELIP families were regulated by the NH4NO3 concentration in the leaves, probably because the high N concentration promoted plant growth. In the root samples, ribosomal proteins were mainly regulated and may have affected sieve tube transport regulation or stress resistance. Changes in the expression levels of NTR and NR family genes corresponded directly to N levels, indicating their important roles as regulatory genes. Nitrogen stress tolerance should be investigated further to understand the importance of N for Tongde development.