Genome-wide analysis and identification of microRNAs in Medicago truncatula under aluminum stress

Zhongjie Lu; Zhengyu Yang; Zheng Tian; Qihui Gui; Rui Dong; Chao Chen

doi:10.3389/fpls.2023.1137764

Genome-wide analysis and identification of microRNAs in Medicago truncatula under aluminum stress

Front Plant Sci. 2023 Jan 27:14:1137764. doi: 10.3389/fpls.2023.1137764. eCollection 2023.

Authors

Zhongjie Lu¹, Zhengyu Yang², Zheng Tian¹, Qihui Gui¹, Rui Dong¹, Chao Chen¹

Affiliations

¹ Department of Grassland Science, College of Animal Science, Guizhou University, Guiyang, China.
² Department of Vehicle Engineering, Guizhou Technological College of Machinery and Electricity, Duyun, China.

Abstract

Numerous studies have shown that plant microRNAs (miRNAs) play key roles in plant growth and development, as well as in response to biotic and abiotic stresses; however, the role of miRNA in legumes under aluminum (Al) stress have rarely been reported. Therefore, here, we aimed to investigate the role of miRNAs in and their mechanism of Al tolerance in legumes. To this end, we sequenced a 12-strand-specific library of Medicago truncatula under Al stress. A total of 195.80 M clean reads were obtained, and 876 miRNAs were identified, of which, 673 were known miRNAs and 203 were unknown. A total of 55 miRNAs and their corresponding 2,502 target genes were differentially expressed at various time points during Al stress. Further analysis revealed that mtr-miR156g-3p was the only miRNA that was significantly upregulated at all time points under Al stress and could directly regulate the expression of genes associated with root cell growth. Three miRNAs, novel_miR_135, novel_miR_182, and novel_miR_36, simultaneously regulated the expression of four Al-tolerant transcription factors, GRAS, MYB, WRKY, and bHLH, at an early stage of Al stress, indicating a response to Al stress. In addition, legume-specific miR2119 and miR5213 were involved in the tolerance mechanism to Al stress by regulating F-box proteins that have protective effects against stress. Our results contribute to an improved understanding of the role of miRNAs in Al stress in legumes and provide a basis for studying the molecular mechanisms of Al stress regulation.

Keywords: Medicago truncatula; aluminum stress; plant growth; plant miRNA; transcript analysis.

Grants and funding

This research was supported by the National Natural Science Foundation of China (32060392) and Support by Guizhou Province Science and Technology Projects (Qian Ke He Zhi Cheng [2020]1Y074) and GZMARS- Forage Industry Technology System.