Institute of Biochemical Plant Pathology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany.
Protoplasma. 2010 Mar;239(1-4):81-93. doi: 10.1007/s00709-009-0085-0. Epub 2009 Nov 25.
This paper investigates differences in gene expression among the two Thlaspi caerulescens ecotypes La Calamine (LC) and Lellingen (LE) that have been shown to differ in metal tolerance and metal uptake. LC originates from a metalliferous soil and tolerates higher metal concentrations than LE which originates from a non-metalliferous soil. The two ecotypes were treated with different levels of zinc in solution culture, and differences in gene expression were assessed through application of a cDNA microarray consisting of 1,700 root and 2,700 shoot cDNAs. Hybridisation of root and shoot cDNA from the two ecotypes revealed a total of 257 differentially expressed genes. The regulation of selected genes was verified by quantitative reverse transcriptase polymerase chain reaction. Comparison of the expression profiles of the two ecotypes suggests that LC has a higher capacity to cope with reactive oxygen species and to avoid the formation of peroxynitrite. Furthermore, increased transcripts for the genes encoding for water channel proteins could explain the higher Zn tolerance of LC compared to LE. The higher Zn tolerance of LC was reflected by a lower expression of the genes involved in disease and defence mechanisms. The results of this study provide a valuable set of data that may help to improve our understanding of the mechanisms employed by plants to tolerate toxic concentrations of metal in the soil.
本研究调查了两种天蓝遏蓝菜（Thlaspi caerulescens）生态型——拉卡明（LC）和莱灵（LE）之间的基因表达差异。这两种生态型在金属耐受性和金属吸收方面存在差异，LC 来源于富含金属的土壤，能够耐受更高的金属浓度，而 LE 则来源于非富含金属的土壤。我们将这两种生态型在溶液培养中用不同水平的锌进行处理，并通过应用包含 1700 个根和 2700 个芽 cDNA 的 cDNA 微阵列来评估基因表达的差异。对来自这两个生态型的根和芽 cDNA 的杂交揭示了总共 257 个差异表达的基因。通过定量逆转录聚合酶链反应验证了所选基因的调控。对两个生态型的表达谱进行比较表明，LC 具有更高的应对活性氧和避免过氧亚硝酸盐形成的能力。此外，水通道蛋白基因的转录增加可以解释 LC 比 LE 具有更高的 Zn 耐受性。LC 的更高 Zn 耐受性反映在参与疾病和防御机制的基因表达较低。本研究的结果提供了一组有价值的数据，可能有助于提高我们对植物在土壤中耐受有毒金属浓度所采用的机制的理解。
