MicroRNA268 Overexpression Affects Rice Seedling Growth under Cadmium Stress
MicroRNA268 Overexpression Affects Rice Seedling Growth under Cadmium Stress
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MicroRNA268 过表达影响镉胁迫下的水稻幼苗生长
DOI：
10.1021/acs.jafc.7b01164
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发表时间：
2017-07-26
影响因子：
6.1
通讯作者：
Zhu, Cheng
中科院分区：
文献类型：
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作者：
Ding, Yanfei;Wang, Yi;Zhu, Cheng
MicroRNA (miRNA) 是 21-24 个核苷酸长的 RNA，作为植物和动物中普遍存在的基因表达转录后调节因子。越来越多的证据表明 miRNA 在植物对非生物和生物胁迫的反应中发挥着重要作用。镉 (Cd) 是一种对植物有剧毒的非必需重金属。尽管许多编码金属转运蛋白的基因已被表征，但重金属转运蛋白基因表达的调节机制在很大程度上是未知的。在本研究中，我们发现水稻中miR268的表达在镉胁迫下显着诱导。相比之下，天然抗性相关巨噬细胞蛋白 3 (NRAMP3)（miR268 的靶基因）的表达在镉处理后显着降低。 miR268 的过表达抑制镉胁迫下的水稻幼苗生长。与野生型植物相比，过表达miR268的转基因植物叶子中过氧化氢和丙二醛的含量增加，并且它们的幼苗积累的镉水平也增加。这些结果表明 miR268 作为水稻对 Cd 胁迫耐受性的负调节因子。因此，miRNA引导的基因表达调控在植物对重金属胁迫的反应中发挥着重要作用。
MicroRNAs (miRNAs) are 21-24-nucleotide-long RNAs that function as ubiquitous post-transcriptional regulators of gene expression in plants and animals. Increasing evidence points to the important role of miRNAs in plant responses to abiotic and biotic stresses. Cadmium (Cd) is a nonessential heavy metal highly toxic to plants. Although many genes encoding metal transporters have been characterized, the mechanisms for the regulation of the expression of the heavy-metal transporter genes are largely unknown. In this study, we found that the expression of miR268 in rice was significantly induced under Cd stress. By contrast, expression of natural resistance-associated macrophage protein 3 (NRAMP3), a target gene of miR268, was dramatically decreased by Cd treatment. Overexpression of miR268 inhibited rice seedling growth under Cd stress. The transgenic miR268-overexpressing plant leaves contained increased levels of hydrogen peroxide and malondialdehyde, and their seedlings accumulated increased levels of Cd when compared to those in wild-type plants. These results indicate that miR268 acts as a negative regulator of rice's tolerance to Cd stress. Thus, miRNA-guided regulation of gene expression plays an important role in plant responses to heavy-metal stress.