Institut de Recherche pour le Développement, Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes, Montpellier, France.
PLoS One. 2013 May 7;8(5):e61932. doi: 10.1371/journal.pone.0061932. Print 2013.
Lead is a heavy metal of particular concern with respect to environmental quality and health. The lack of plant species that accumulate and tolerate Pb is a limiting factor to understand the molecular mechanisms involved in Pb tolerance. In this study we identified Hirschfeldia incana, a Brassicaceae collected from metalliferous mine spoils in Morocco, as a Pb accumulator plant. H. incana exhibited high Pb accumulation in mine soils and in hydroponic cultures. Major Pb accumulation occurred in the roots and a part of Pb translocated from the roots to the shoots, even to the siliques. These findings demonstrated that H. incana is a Pb accumulator species. The expression of several candidate genes after Pb-exposure was measured by quantitative PCR and two of them, HiHMA4 and HiMT2a, coding respectively for a P1B-type ATPase and a metallothionein, were particularly induced by Pb-exposure in both roots and leaves. The functional characterization of HiHMA4 and HiMT2a was achieved using Arabidopsis T-DNA insertional mutants. Pb content and primary root growth analysis confirmed the role of these two genes in Pb tolerance and accumulation. H. incana could be considered as a good experimental model to identify genes involved in lead tolerance and accumulation in plants.
铅是一种重金属，特别关注其对环境质量和健康的影响。缺乏能够积累和耐受 Pb 的植物物种，是理解 Pb 耐受相关分子机制的一个限制因素。在这项研究中，我们鉴定了 Hirschfeldia incana，一种来自摩洛哥含金属矿渣的十字花科植物，是一种 Pb 积累植物。H. incana 在矿区土壤和水培培养中表现出高 Pb 积累。大部分 Pb 积累在根部，一部分 Pb 从根部转移到地上部分，甚至到种荚。这些发现表明 H. incana 是一种 Pb 积累物种。通过定量 PCR 测量 Pb 暴露后几个候选基因的表达，其中两个基因，HiHMA4 和 HiMT2a，分别编码 P1B 型 ATP 酶和金属硫蛋白，在根部和叶片中均被 Pb 暴露强烈诱导。使用拟南芥 T-DNA 插入突变体对 HiHMA4 和 HiMT2a 的功能进行了表征。Pb 含量和主根生长分析证实了这两个基因在 Pb 耐受和积累中的作用。H. incana 可以被认为是一种很好的实验模型，可用于鉴定植物中参与 Pb 耐受和积累的基因。
