Real-time kinetics of cadmium transport and transcriptomic analysis in low cadmium accumulator Miscanthus sacchariflorus
Real-time kinetics of cadmium transport and transcriptomic analysis in low cadmium accumulator Miscanthus sacchariflorus
复制标题
低镉累积体芒草中镉转运的实时动力学和转录组分析
DOI：
10.1007/s00425-016-2578-3
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发表时间：
2016-12-01
期刊：
影响因子：
4.3
通讯作者：
Jiang, Dean
中科院分区：
文献类型：
--
作者：
Guo, Haipeng;Hong, Chuntao;Jiang, Dean
利用RNA测序技术揭示了芒草低镉流入和积累的分子机制。土壤镉污染已对土壤质量、粮食安全以及人类健康构成严重威胁。一些野生植物对重金属胁迫表现出较高的耐受性。然而，野生植物耐Cd的机制尚不完全清楚。本研究发现，芒种sacchariflorus和M. floridulus表现出不同的cd耐受机制。糖花菊通过限制根对Cd的吸收，在根和叶中积累的Cd较少，表现出较强的Cd耐受性，而花菊不仅从根中吸收更多的Cd，而且向地上部输送更多的Cd。为了研究两种芒草不同Cd摄取模式的分子机制，我们分析了M. sacchariflorus的转录组，并利用高通量rna测序技术鉴定了根内Cd响应的转录变化。从sacchariflorus根cDNA样本中共获得92,985个单基因。根据组装的从头转录组，在未处理和cd处理的两个根文库中检测到681个deg，其中345个基因上调，336个基因下调。基因本体（GO）和途径富集分析表明，Cd胁迫下DEGs的上调主要与代谢途径、淀粉和蔗糖以及次生代谢物和金属离子转运体的生物合成有关。采用定量RT-PCR方法比较了两种芒草根中部分金属转运基因的表达水平，发现参与从根吸收Cd和从根向地上部转移Cd的基因差异极大。该结果不仅丰富了基因组资源，而且有助于更好地了解野生植物Cd积累和耐受的分子机制。
The molecular mechanism of low Cd influxes and accumulation in Miscanthus sacchariflorus is revealed by RNA sequencing technique.Soil cadmium (Cd) pollution has posed a serious threat to our soil quality and food security as well as to human health. Some wild plants exhibit high tolerance to heavy metals stress. However, mechanisms of Cd tolerance of wild plants remain to be fully clarified. In this study, we found that two Miscanthus species, Miscanthus (M.) sacchariflorus and M. floridulus, showed different Cd-tolerant mechanisms. M. sacchariflorus accumulated less Cd in both root and leaf by limiting Cd uptake from root and showed superior Cd tolerance, while M. floridulus not only absorbs more Cd from root but also transports more Cd to shoot. To investigate the molecular mechanism of different Cd uptake patterns in the two Miscanthus species, we analyzed the transcriptome of M. sacchariflorus and identified transcriptional changes in response to Cd in roots by high-throughput RNA-sequencing technology. A total of 92,985 unigenes were obtained from M. sacchariflorus root cDNA samples. Based on the assembled de novo transcriptome, 681 DEGs which included 345 upregulated and 336 downregulated genes were detected between two libraries of untreated and Cd-treated roots. Gene ontology (GO) and pathway enrichment analysis revealed that upregulated DEGs under Cd stress are predominately involved in metabolic pathway, starch and sucrose and biosynthesis of secondary metabolites and metal ion transporters. Quantitative RT-PCR was employed to compare the expression levels of some metal transport genes in roots of two Miscanthus species, and the genes involved in Cd uptake from root and transfer from root to shoot were extremely different. The results not only enrich genomic resource but also help to better understand the molecular mechanisms of Cd accumulation and tolerance in wild plants.