Pegler Joseph L, Oultram Jackson M J, Nguyen Duc Quan, Grof Christopher P L, Eamens Andrew L
Centre For Plant Science, School of Environmental and Life Sciences, Faculty of Science, University of Newcastle, Callaghan, NSW 2308, Australia.
Institute of Genome Research, Vietnam Academy of Research and Technology, 18 Hoang Quoc Viet Str., Cau Giay, Hanoi 100000, Vietnam.
Plants (Basel). 2021 Jan 10;10(1):130. doi: 10.3390/plants10010130.
In recent decades, the presence of cadmium (Cd) in the environment has increased significantly due to anthropogenic activities. Cd is taken up from the soil by plant roots for its subsequent translocation to shoots. However, Cd is a non-essential heavy metal and is therefore toxic to plants when it over-accumulates. MicroRNA (miRNA)-directed gene expression regulation is central to the response of a plant to Cd stress. Here, we document the miRNA-directed response of wild-type () plants and the , and mutant lines to Cd stress. Phenotypic and physiological analyses revealed the mutant to display the highest degree of tolerance to the imposed stress while the mutant was the most sensitive. RT-qPCR-based molecular profiling of miRNA abundance and miRNA target gene expression revealed DRB1 to be the primary double-stranded RNA binding (DRB) protein required for the production of six of the seven Cd-responsive miRNAs analyzed. However, DRB2, and not DRB1, was determined to be required for miR396 production. RT-qPCR further inferred that transcript cleavage was the RNA silencing mechanism directed by each assessed miRNA to control miRNA target gene expression. Taken together, the results presented here reveal the complexity of the miRNA-directed molecular response of to Cd stress.
近几十年来，由于人类活动，环境中镉（Cd）的含量显著增加。植物根系从土壤中吸收Cd，随后将其转运到地上部分。然而，Cd是一种非必需重金属，因此当它过度积累时对植物有毒。微小RNA（miRNA）介导的基因表达调控是植物对Cd胁迫响应的核心。在此，我们记录了野生型（）植物以及、和突变系对Cd胁迫的miRNA介导的响应。表型和生理分析表明，突变体对施加的胁迫表现出最高程度的耐受性，而突变体最敏感。基于RT-qPCR的miRNA丰度和miRNA靶基因表达的分子分析表明，DRB1是所分析的7种Cd响应miRNA中的6种产生所需的主要双链RNA结合（DRB）蛋白。然而，已确定miR396的产生需要DRB2而不是DRB1。RT-qPCR进一步推断，转录本切割是每种评估的miRNA指导的RNA沉默机制，以控制miRNA靶基因表达。综上所述，本文呈现的结果揭示了对Cd胁迫的miRNA介导的分子响应的复杂性。
