Transcriptome analysis and physiological changes in the leaves of two Bromus inermis L. genotypes in response to salt stress

Wenxue Song; Xueqin Gao; Huiping Li; Shuxia Li; Jing Wang; Xing Wang; Tongrui Wang; Yunong Ye; Pengfei Hu; Xiaohong Li; Bingzhe Fu

doi:10.3389/fpls.2023.1313113

Transcriptome analysis and physiological changes in the leaves of two Bromus inermis L. genotypes in response to salt stress

Front Plant Sci. 2023 Dec 14:14:1313113. doi: 10.3389/fpls.2023.1313113. eCollection 2023.

Authors

Wenxue Song¹, Xueqin Gao^{1

2}, Huiping Li¹, Shuxia Li^{1

2}, Jing Wang¹, Xing Wang¹, Tongrui Wang¹, Yunong Ye¹, Pengfei Hu¹, Xiaohong Li¹, Bingzhe Fu^{1

2

3}

Affiliations

¹ College of Forestry and Prataculture, Ningxia University, Yinchuan, Ningxia, China.
² Ningxia Grassland and Animal Husbandry Engineering Technology Research Center, Yinchuan, Ningxia, China.
³ Key Laboratory for Model Innovation in Forage Production Efficiency, Ministry of Agriculture and Rural Affairs, Yinchuan, Ningxia, China.

Abstract

Soil salinity is a major factor threatening the production of crops around the world. Smooth bromegrass (Bromus inermis L.) is a high-quality grass in northern and northwestern China. Currently, selecting and utilizing salt-tolerant genotypes is an important way to mitigate the detrimental effects of salinity on crop productivity. In our research, salt-tolerant and salt-sensitive varieties were selected from 57 accessions based on a comprehensive evaluation of 22 relevant indexes, and their salt-tolerance physiological and molecular mechanisms were further analyzed. Results showed significant differences in salt tolerance between 57 genotypes, with Q25 and Q46 considered to be the most salt-tolerant and salt-sensitive accessions, respectively, compared to other varieties. Under saline conditions, the salt-tolerant genotype Q25 not only maintained significantly higher photosynthetic performance, leaf relative water content (RWC), and proline content but also exhibited obviously lower relative conductivity and malondialdehyde (MDA) content than the salt-sensitive Q46 (p < 0.05). The transcriptome sequencing indicated 15,128 differentially expressed genes (DEGs) in Q46, of which 7,885 were upregulated and 7,243 downregulated, and 12,658 DEGs in Q25, of which 6,059 were upregulated and 6,599 downregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the salt response differences between Q25 and Q46 were attributed to the variable expression of genes associated with plant hormone signal transduction and MAPK signaling pathways. Furthermore, a large number of candidate genes, related to salt tolerance, were detected, which involved transcription factors (zinc finger proteins) and accumulation of compatible osmolytes (glutathione S-transferases and pyrroline-5-carboxylate reductases), etc. This study offers an important view of the physiological and molecular regulatory mechanisms of salt tolerance in two smooth bromegrass genotypes and lays the foundation for further identification of key genes linked to salt tolerance.

Keywords: Bromus inermis L.; accessions evaluation; physiological analysis; salt stress; transcriptome analysis.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Ningxia Agricultural Breeding Special Project (2019NYYZ0403).