Genome-wide identification of Cd-responsive NRAMP transporter genes and analyzing expression of NRAMP 1 mediated by miR167 in Brassica napus
Genome-wide identification of Cd-responsive NRAMP transporter genes and analyzing expression of NRAMP 1 mediated by miR167 in Brassica napus
复制标题
甘蓝型油菜中 Cd 响应 NRAMP 转运蛋白基因的全基因组鉴定并分析 miR167 介导的 NRAMP 1 表达
DOI：
10.1007/s10534-017-0057-3
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发表时间：
2017-12-01
期刊：
影响因子：
3.5
通讯作者：
Yang, Zhi Min
中科院分区：
文献类型：
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作者：
Meng, Jin Guo;Zhang, Xian Duo;Yang, Zhi Min
在植物中，金属转运蛋白负责金属摄取，易位和稳态。这些金属包括锌（Zn）和锰（MN）等必需营养素，或镉（CD）和铅（PB）等非必需金属。尽管在模型植物中有一些金属转运蛋白的表征，但对它们在Rapeseed（Brassica Napus）中的功能知之甚少。在这项研究中，使用生物信息学和高通量RNA测序（RNA-Seq）鉴定了22个NRAMP转运蛋白基因并注释。基于序列身份，这些NRAMP转运蛋白可以分为6个亚家族。 RNA-Seq分析表明，检测到19个NRAMP转运蛋白，其中一些基因通过QRT-PCR很好地证实。在CD暴露下，发现十个NRAMP转运蛋白（45.5％，10/22）在CD暴露下差异表达（> 2倍变化，p <0.05）。例如，我们指定了CD暴露下BNNRAMP1B的表达。 Bnnramp1b是一种本构基因，在所有发育阶段都表达，包括幼苗，营养组织，花和硅烷。在暴露于80、160和240 mu m cd的幼苗中，Bnnramp1b的表达可以强烈诱导。为了定义BNNRAMP1B是否针对CD转运，分别测试了CD，Zn和Mn的转运活性有缺陷的酵母（野生型，By4741）系统。与空载体（PYES2）相比，携带BnnRamp1b的细胞可以挽救运输功能。结果，在细胞中取出过多的Cd，Zn和Mn，这导致了金属毒性，这表明BNNRAMP1B负责在乳芽孢杆菌中运输这些金属。使用我们先前创建的降解组数据集，我们发现BNNRAMP1B可以被MiR167裂解，这表明Bnnramp1b是B. Napus中Mir167的靶标。 CD应力下BNNRAMP1B和MIR167的对比表达模式支持MiR167对BNNRAMP1B的转录后调节。
In plants, metal transporters are responsible for metal uptake, translocation and homeostasis. These metals include essential nutrients such as zinc (Zn) and manganese (Mn) or non-essential metals like cadmium (Cd) and lead (Pb). Although a few metal transporters have been well characterized in model plants, little is known about their functionality in rapeseed (Brassica napus). In the study, 22 NRAMP transporter genes from B. napus genome were identified and annotated using bioinformatics and high-throughput RNA-sequencing (RNA-seq). Based on the sequence identity, these NRAMP transporters can be classified into 6 subfamilies. RNA-seq analysis revealed that 19 NRAMP transporters were detected and some of the genes were well confirmed by qRT-PCR. Ten NRAMP transporters (45.5%, 10/22) were found to be differentially expressed (> 2 fold change, p < 0.05) under Cd exposure. As an example, we specified expression of BnNRAMP1b under Cd exposure. BnNRAMP1b is a constitutive gene expressing throughout all development stages including seedlings, vegetative tissue, flowers and siliques. Expression of BnNRAMP1b can be strongly induced in seedlings exposed to 80, 160 and 240 μM Cd. To define whether BnNRAMP1b was specific for Cd transport, a yeast (wild-type, BY4741) system with its mutants (ycf1, zrc1, and smf1) defective in transport activity of Cd, Zn and Mn, respectively were tested. Compared to empty vectors (pYES2), cells carrying BnNRAMP1b can rescue the transport functions. As a consequence, excess Cd, Zn and Mn were taken in the cells, which led to metal toxicity, suggesting that BnNRAMP1b is responsible for transport of these metals in B. napus. Using our previously created degradome datasets, we found that BnNRAMP1b could be cleaved by miR167, suggesting that BnNRAMP1b is a target of miR167 in B. napus. The contrasting expression pattern of BnNRAMP1b and miR167 under Cd stress supported the post-transcriptional regulation of BnNRAMP1b by miR167.