Liu Zhongyuan, Xu Ruiting, Fan Yingbo, Dong Wenfang, Han Yating, Xie Qingjun, Li Jinghang, Liu Baichao, Wang Chao, Wang Yucheng, Fu Yujie, Gao Caiqiu
State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin 150040, PR China.
Key Laboratory of Forestry Plant Ecology, Ministry of Education (Northeast Forestry University), Harbin 150040, PR China.
Tree Physiol. 2024 Feb 6;44(1). doi: 10.1093/treephys/tpad159.
The microRNAs, which are small RNAs of 18-25 nt in length, act as key regulatory factors in posttranscriptional gene expression during plant growth and development. However, little is known about their regulatory roles in response to stressful environments in birch (Betula platyphylla). Here, we characterized and further explored miRNAs from osmotic- and salt-stressed birch. Our analysis revealed a total of 190 microRNA (miRNA) sequences, which were classified into 180 conserved miRNAs and 10 predicted novel miRNAs based on sequence homology. Furthermore, we identified Bp-miR408a under osmotic and salt stress and elucidated its role in osmotic and salt stress responses in birch. Notably, under osmotic and salt stress, Bp-miR408a contributed to osmotic and salt tolerance sensitivity by mediating various physiological changes, such as increases in reactive oxygen species accumulation, osmoregulatory substance contents and Na+ accumulation. Additionally, molecular analysis provided evidence of the in vivo targeting of BpBCP1 (blue copper protein) transcripts by Bp-miR408a. The overexpression of BpBCP1 in birch enhanced osmotic and salt tolerance by increasing the antioxidant enzyme activity, maintaining cellular ion homeostasis and decreasing lipid peroxidation and cell death. Thus, we reveal a Bp-miR408a-BpBCP1 regulatory module that mediates osmotic and salt stress responses in birch.
微小RNA是长度为18 - 25个核苷酸的小RNA，在植物生长发育过程中作为转录后基因表达的关键调控因子。然而，关于它们在白桦（Betula platyphylla）应对胁迫环境中的调控作用知之甚少。在此，我们对白桦在渗透胁迫和盐胁迫下的微小RNA进行了表征和进一步探索。我们的分析共揭示了190个微小RNA（miRNA）序列，基于序列同源性将其分为180个保守miRNA和10个预测的新miRNA。此外，我们鉴定了渗透和盐胁迫下的Bp-miR408a，并阐明了其在白桦渗透和盐胁迫响应中的作用。值得注意的是，在渗透和盐胁迫下，Bp-miR408a通过介导各种生理变化，如活性氧积累增加、渗透调节物质含量增加和Na +积累，导致渗透和盐耐受性敏感。此外，分子分析提供了Bp-miR408a在体内靶向BpBCP1（蓝铜蛋白）转录本的证据。白桦中BpBCP1的过表达通过提高抗氧化酶活性、维持细胞离子稳态以及减少脂质过氧化和细胞死亡来增强渗透和盐耐受性。因此，我们揭示了一个介导白桦渗透和盐胁迫响应的Bp-miR408a - BpBCP1调控模块。
