Assunção Ana G L, Ten Bookum Wilma M, Nelissen Hans J M, Vooijs Riet, Schat Henk, Ernst Wilfried H O
Department of Ecology and Physiology of Plants, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1087, NL-1081 HV Amsterdam, The Netherlands.
New Phytol. 2003 Aug;159(2):383-390. doi: 10.1046/j.1469-8137.2003.00758.x.
• To analyse the relation between zinc (Zn) accumulation and Zn tolerance in the Zn hyperaccumulator, Thlaspi caerulescens, a cross was made between a plant from a nonmetallicolous population (LE: high accumulation, low tolerance) and one from a calamine population (LC: low accumulation, high tolerance). • More or less homogeneous F lines with contrasting extreme accumulation phenotypes were selected and phenotyped for tolerance, using the threshold exposure level for chlorosis as a tolerance measure. Zn accumulation and tolerance segregated largely independently, although there was a significant degree of association between low accumulation and high tolerance. • Plants from an F family were phenotyped for Zn tolerance and their Zn accumulation rates were compared. The plants with low Zn tolerance exhibited significantly higher Zn accumulation than did the more tolerant plants. • The results suggest that the superior Zn tolerance in LC plants compared with LE plants results from a superior plant-internal Zn sequestration capacity and, although to a lower degree, a reduced rate of Zn accumulation. It is argued that the relatively low Zn accumulation capacity levels found in LC and several other calamine T. caerulescens populations might represent an adaptive response to Zn-toxic soil.
• 为了分析锌超富集植物天蓝遏蓝菜中锌（Zn）积累与锌耐受性之间的关系，将来自非矿质土壤种群（LE：高积累、低耐受性）的植株与来自炉甘石种群（LC：低积累、高耐受性）的植株进行杂交。• 选择了具有不同极端积累表型的大致同质的F品系，并以褪绿的阈值暴露水平作为耐受性指标，对其耐受性进行表型分析。锌积累和耐受性在很大程度上是独立分离的，尽管低积累和高耐受性之间存在显著程度的关联。• 对一个F家族的植株进行锌耐受性表型分析，并比较它们的锌积累速率。锌耐受性低的植株比耐受性更强的植株表现出显著更高的锌积累。• 结果表明，与LE植株相比，LC植株具有更强的锌耐受性是由于其更强的植物体内锌螯合能力，并且尽管程度较低，但锌积累速率也有所降低。有人认为，在LC和其他几个炉甘石天蓝遏蓝菜种群中发现的相对较低的锌积累能力水平可能代表了对锌毒性土壤的一种适应性反应。
