Biotechnology Bulletin ›› 2025, Vol. 41 ›› Issue (2): 139-149.doi: 10.13560/j.cnki.biotech.bull.1985.2024-0584

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Mechanism of miR172b/c-BnMSH7.A1 Module Responding to Cu 2+ Stress in Brassica napus

LIU Fang1,2(), DU Qian-qian1, HE Hao1, XIAO Gang3, YAN Zhong-yuan1(), HAO Xiao-hua1()   

  1. 1.College of Life and Environmental Science, Hunan University of Arts and Science, Changde 415000
    2.Changde Research Centre Agricultural Biological Macromolecule, Changde 415000
    3.College of Agriculture, Hunan Agriculture Universtity, Changsha 410000
  • Received:2024-06-17 Online:2025-02-26 Published:2025-02-28
  • Contact: YAN Zhong-yuan, HAO Xiao-hua E-mail:g5n2a5f@163.com;7637188893@qq.com;14771417@qq.com

Abstract:

Objective To explore the mechanism of miRNA regulation in response to Cu2+stress in Brassica napusBnMSH7.A1, and to provide new research ideas for exploring the regulatory function of miRNA in response to heavy metal stress. Method The BnMSH7 gene was cloned from B. napus, bioinformatics methods were used to analyze its sequence characteristics and potential functions, and to predict and screen the candidate miRNAs regulating the BnMSH7 gene in B. napus, which was verified by the tobacco dual luciferase reporter system in vitro. Pre-miR172b and pre-miR172c were transfected into rape cotyledons for in vivo validation. Rape seedlings were treated with different concentrations of Cu2+, and qRT-PCR was used to detect the expressions of miR172b, miR172c, and BnMSH7.A1. Correlation analysis was conducted to infer the regulation of BnMSH7.A1 by miR172b and miR172c under Cu2+stress. Result It was found that the ratio of fluorescence values of wild-type fireflies (Watasenia scintillans) to sea kidney (Renilla reniformis) fluorescence values significantly decreased compared to the blank control, indicating that BnMSH7.A1 was regulated by miR172b and miR172c. Meanwhile, in vivo validation revealed that the expression patterns of miR172b and miR172c were opposite to those of BnMSH7.A1, exhibiting inhibitory regulation, further indicating that miR172b and miR172c regulated BnMSH7.A1. According to bioinformatics predictions, copper responsive elements were found on the promoters of miR172b, miR172c, and BnMSH7.A1. After Cu2+treatment, pre-miR172b and pre-miR172c in roots positively regulated miR172b and miR172c, respectively, further promoting the expression of BnMSH7.A1. MiR172b and miR172c in the leaves negatively regulated the expressions of BnMSH7.A1, and pre-miR172b and pre-miR172c showed negative regulation with miR172b and miR172c, but not significantly. Conclusion The regulatory mode of miR172b/c-BnMSH7.A1 module varies in different organizations. In the root, pre-miR172b and pre-miR172c are positively correlated with miR172b and miR172c, and miR172b/c can positively regulate the expression of BnMSH7.A1. There is no significant correlation between pre-miR172b, pre-miR172c, and miR172b/c in the leaves, but miR172b/c can negatively regulate the expression of BnMSH7.A1.

Key words: Cu2+ stress, BnMSH7.A1, miR172b/c, double luciferase reporter assay analysis, correlation analysis