Kohler Annegret, Blaudez Damien, Chalot Michel, Martin Francis
UMR INRA/Université Henri Poincaré 1136, Interactions Arbres/Micro-organismes, Centre INRA de Nancy, F-54280 Champenoux, France.
New Phytol. 2004 Oct;164(1):83-93. doi: 10.1111/j.1469-8137.2004.01168.x.
• In an effort to understand processes that are related to heavy metal sequestration, we characterized six metallothionein genes (PtdMTs) in the hybrid cottonwood, Populus trichocarpa × deltoides. • cDNA microarrays and reverse transcriptase-polymerase chain reaction were used to examine PtdMT expression in poplar tissues. They displayed differential gene expression patterns, which may be associated with the diverse roles and functions PtdMTs have in coping with particular developmental (e.g. root development and leaf senescence) and environmental cues. • The heterologous expression in a cadmium (Cd)-hypersensitive yeast mutant showed the ability of PtdMT cDNAs to confer Cd tolerance. The concentration of PtdMT mRNAs were increased by zinc, but not by copper and Cd. • Further studies will help to clarify the role of metallothionein genes in metal homeostasis and poplar development, and help to isolate poplar genotypes particularly tolerant to stress for use in experiments of phytoremediation.
为了了解与重金属螯合相关的过程，我们对杂交杨树毛果杨×美洲黑杨中的六个金属硫蛋白基因（PtdMTs）进行了表征。利用cDNA微阵列和逆转录聚合酶链反应检测杨树组织中PtdMT的表达。它们表现出差异基因表达模式，这可能与PtdMTs在应对特定发育（如根系发育和叶片衰老）和环境信号方面的多种作用和功能有关。在对镉（Cd）敏感的酵母突变体中的异源表达表明PtdMT cDNA具有赋予Cd耐受性的能力。PtdMT mRNA的浓度因锌而增加，但不受铜和镉的影响。进一步的研究将有助于阐明金属硫蛋白基因在金属稳态和杨树发育中的作用，并有助于分离出对胁迫具有特别耐受性的杨树基因型，用于植物修复实验。
