Xu Pengfei, Zhang Wenting, Wang Xuan, Zhu Yantao, Liang Wanqi, He Yuke, Yu Xiang
Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Plant Cell Environ. 2023 Nov;46(11):3405-3419. doi: 10.1111/pce.14690. Epub 2023 Aug 11.
Brassica crops include various edible vegetable and plant oil crops, and their production is limited by low temperature beyond their tolerant capability. The key regulators of low-temperature resistance in Brassica remain largely unexplored. To identify posttranscriptional regulators of plant response to low temperature, we performed small RNA profiling, and found that 16 known miRNAs responded to cold treatment in Brassica rapa. The cold response of seven of those miRNAs were further confirmed by qRT-PCR and/or northern blot analyses. In parallel, a genome-wide association study of 220 accessions of Brassica napus identified four candidate MIRNA genes, all of which were cold-responsive, at the loci associated with low-temperature resistance. Specifically, these large-scale data analyses revealed a link between miR1885 and the plant response to low temperature in both B. rapa and B. napus. Using 5' rapid amplification of cDNA ends approach, we validated that miR1885 can cleave its putative target gene transcripts, Bn.TIR.A09 and Bn.TNL.A03, in B. napus. Furthermore, overexpression of miR1885 in Semiwinter type B. napus decreased the mRNA abundance of Bn.TIR.A09 and Bn.TNL.A03 and resulted in increased sensitivity to low temperature. Knocking down of miR1885 in Spring type B. napus led to increased mRNA abundance of its targets and improved rapeseed tolerance to low temperature. Together, our results suggested that the loci of miR1885 and its targets could be potential candidates for the molecular breeding of low temperature-tolerant Spring type Brassica crops.
十字花科作物包括各种可食用蔬菜和植物油作物，其产量受到超出耐受能力的低温限制。十字花科中低温抗性的关键调节因子在很大程度上仍未得到探索。为了鉴定植物对低温响应的转录后调节因子，我们进行了小RNA分析，发现16种已知的miRNA在白菜中对冷处理有响应。其中7种miRNA的冷响应通过qRT-PCR和/或Northern印迹分析进一步得到证实。同时，对220份甘蓝型油菜种质进行全基因组关联研究，在与低温抗性相关的位点鉴定出4个候选MIRNA基因，所有这些基因均对低温有响应。具体而言，这些大规模数据分析揭示了miR1885与白菜和甘蓝型油菜中植物对低温响应之间的联系。使用5' cDNA末端快速扩增方法，我们验证了miR1885可以切割其假定的靶基因转录本，即甘蓝型油菜中的Bn.TIR.A09和Bn.TNL.A03。此外，在半冬性甘蓝型油菜中过表达miR1885降低了Bn.TIR.A09和Bn.TNL.A03的mRNA丰度，并导致对低温的敏感性增加。在春性甘蓝型油菜中敲低miR1885导致其靶标的mRNA丰度增加，并提高了油菜对低温的耐受性。总之，我们的结果表明，miR1885及其靶标的位点可能是耐低温春性十字花科作物分子育种的潜在候选者。
