Vogel-Mikus Katarina, Pongrac Paula, Kump Peter, Necemer Marijan, Simcic Jure, Pelicon Primoz, Budnar Milos, Povh Bogdan, Regvar Marjana
Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana, Slovenia.
Environ Pollut. 2007 May;147(1):50-9. doi: 10.1016/j.envpol.2006.08.026. Epub 2006 Oct 27.
Cd, Zn and Pb accumulation, spatial distribution within seeds and germinating seedlings, and seeds fitness of metal hyperaccumulating Thlaspi praecox were investigated in order to gain more knowledge on plant reproductive success at metal polluted sites. The seeds contained up to 1351 microg g-1 (dry weight) of Cd, 121 microg g-1 of Zn and 17 microg g-1 of Pb. Seed fitness was negatively influenced by seed Cd hyperaccumulation. Nevertheless, the viability of seeds was decreased by maximally 20%, indicating very efficient tolerance of the plant embryos to Cd. Localisation by micro-PIXE revealed preferential storage of most elements in the embryonic axis. Cd and Zn were preferentially localised in the epidermis of cotyledons. The restriction of seed Pb and Zn uptake and hyperaccumulation of Cd, accompanied by partitioning of Cd in the epidermal tissues of cotyledons, may enable the survival of T. praecox embryos and seedlings in Cd polluted environments.
为了更深入了解金属污染场地中植物的繁殖成功情况，对金属超积累植物早花菥蓂种子及萌发幼苗中镉（Cd）、锌（Zn）和铅（Pb）的积累、空间分布以及种子适合度进行了研究。种子中镉含量高达1351微克/克（干重），锌含量为121微克/克，铅含量为17微克/克。种子适合度受到种子镉超积累的负面影响。然而，种子活力最大降低了20%，这表明植物胚胎对镉具有非常有效的耐受性。微束质子激发X射线发射（micro-PIXE）定位显示，大多数元素优先储存在胚轴中。镉和锌优先定位在子叶表皮中。种子对铅和锌吸收的限制以及镉的超积累，同时镉在子叶表皮组织中的分配，可能使早花菥蓂胚胎和幼苗在镉污染环境中存活。
