Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Plant Physiol Biochem. 2012 Jan;50(1):79-86. doi: 10.1016/j.plaphy.2011.07.015. Epub 2011 Aug 9.
Cadmium (Cd), a non-essential metal, is a kind of toxic heavy metal to life, which can accumulate in rice tissues including seeds, thus posing a risk to human health through food chain. To investigate the molecular mechanisms of rice response to Cd exposure, suppression subtractive hybridization and mirror orientation selection were used to compare gene expression profiles in seedling roots of Cd-exposed and control (unexposed) rice plants (Oryza sativa L., Nipponbare). Approximately 1700 positive clones, with insertions ranging from 250 to 1300 bp, were identified through reverse cDNA microarray analysis. Gene expression was further confirmed by real time RT-PCR. A number of differentially expressed genes were found in Cd-exposed rice roots, including 28 up-regulated genes and 19 down-regulated genes. They were found to be involved in diverse biological processes, such as metabolism, stress response, ion transport and binding, protein structure and synthesis, as well as signal transduction. Notably a number of known functional genes were identified encoding membrane proteins and stress-related proteins such as heat shock proteins, monosaccharide transporters, CBL-interacting serine/threonine-protein kinases and metal tolerance proteins. The cDNAs isolated in this study contribute to our understanding of genes and the biochemical pathways that may play a key role in the response of plants to metal exposure in the environment.
镉（Cd）是一种非必需的金属，是一种对生命有毒的重金属，它可以在包括种子在内的水稻组织中积累，从而通过食物链对人类健康构成威胁。为了研究水稻对镉暴露的分子机制，我们采用抑制性消减杂交和镜像定向选择的方法，比较了暴露于镉和未暴露（对照）的水稻幼苗根系中的基因表达谱（Oryza sativa L.，Nipponbare）。通过反向 cDNA 微阵列分析，鉴定了约 1700 个阳性克隆，插入片段大小为 250 至 1300 bp。通过实时 RT-PCR 进一步证实了基因表达。在镉暴露的水稻根系中发现了许多差异表达的基因，包括 28 个上调基因和 19 个下调基因。它们被发现参与了多种生物过程，如代谢、应激反应、离子转运和结合、蛋白质结构和合成以及信号转导。值得注意的是，鉴定出了一些编码膜蛋白和应激相关蛋白的已知功能基因，如热休克蛋白、单糖转运蛋白、CBL 相互作用丝氨酸/苏氨酸蛋白激酶和金属耐受蛋白。本研究中分离的 cDNA 有助于我们理解基因和生化途径，这些基因和生化途径可能在植物对环境中金属暴露的反应中发挥关键作用。
