Early gene expression in Pseudomonas fluorescens exposed to a polymetallic solution
Early gene expression in Pseudomonas fluorescens exposed to a polymetallic solution
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DOI：
10.1007/s10565-015-9294-9
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发表时间：
2015-02-01
影响因子：
6.1
通讯作者：
Garbisu, Carlos
中科院分区：
文献类型：
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作者：
Gomez-Sagasti, Maria T.;Becerril, Jose M.;Garbisu, Carlos
暴露于重金属混合物的荧光假单胞菌细胞的分子反应在很大程度上仍然未知。在这里，我们研究了荧光假单胞菌细胞暴露于三个剂量的多金属溶液超过两个曝光时间的早期基因表达的时间变化，通过应用定制的cDNA微阵列。在最低的金属剂量（MD/4），我们观察到的Hsp 70分子伴侣系统，MATE和MFS转运蛋白，TonB膜转运蛋白和组氨酸激酶的抑制，以及金属转运（ChaC，CopC），趋化性和谷氨酰胺合成酶基因的过表达。在中间金属剂量（MD），几个氨基酸转运蛋白，反应调节（CheY），TonB依赖性受体和mutT DNA修复基因被抑制;相比之下，与抗氧化应激系统和螯合物和硫的运输相关的基因的过表达被观察到。最后，在最高的金属剂量（4 MD），抑制编码金属离子转运蛋白，耐药性和藻酸盐生物合成的基因被发现，连同编码抗氧化蛋白，膜转运蛋白，核糖体蛋白，伴侣蛋白和蛋白酶的基因的过度表达。结果表明，荧光假单胞菌细胞在暴露于多金属溶液时，随着暴露时间的延长，表现出高度复杂的分子反应，涉及与趋化性、信号传递、膜转运、细胞氧化还原状态以及转录和核糖体活性调节相关的机制。
The molecular response of Pseudomonas fluorescens cells exposed to a mixture of heavy metals remains largely unknown. Here, we studied the temporal changes in the early gene expression of P. fluorescens cells exposed to three doses of a polymetallic solution over two exposure times, through the application of a customized cDNA microarray. At the lowest metal dose (MD/4), we observed a repression of the Hsp70 chaperone system, MATE and MFS transporters, TonB membrane transporter and histidine kinases, together with an overexpression of metal transport (ChaC, CopC), chemotaxis and glutamine synthetase genes. At the intermediate metal dose (MD), several amino acid transporters, a response regulator (CheY), a TonB-dependent receptor and the mutT DNA repair gene were repressed; by contrast, an overexpression of genes associated with the antioxidative stress system and the transport of chelates and sulfur was observed. Finally, at the highest metal dose (4MD), a repression of genes encoding metal ion transporters, drug resistance and alginate biosynthesis was found, together with an overexpression of genes encoding antioxidative proteins, membrane transporters, ribosomal proteins, chaperones and proteases. It was concluded that P. fluorescens cells showed, over exposure time, a highly complex molecular response when exposed to a polymetallic solution, involving mechanisms related with chemotaxis, signal transmission, membrane transport, cellular redox state, and the regulation of transcription and ribosomal activity.