Stem and leaf sequestration of zinc at the cellular level in the hyperaccumulator Sedum alfredii
Stem and leaf sequestration of zinc at the cellular level in the hyperaccumulator Sedum alfredii
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DOI：
10.1111/j.1469-8137.2008.02740.x
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发表时间：
2009-01-01
期刊：
影响因子：
9.4
通讯作者：
Brown, Patrick
中科院分区：
文献类型：
--
作者：
Tian, Sheng-Ke;Lu, Ling-Li;Brown, Patrick
东南景天是中国原产的一种生长迅速、生物量高的锌超积累植物。利用同步辐射X射线荧光(SRXRF)技术，结合锌探针，研究了超积累生态型(HE)和非超积累生态型(NHE)中锌在茎叶中的分布特征，发现超积累生态型和非超积累生态型叶和茎表皮中锌的积累较多，但超积累生态型中锌的积累程度更大。随着暴露时间的延长，HE叶片和茎中的锌含量显著增加，而叶肉细胞和茎维管束中的锌饱和时间相对较早。在茎和叶维管系统中，两个生态型都出现了第二个锌富集峰。而在茎维管束中积累的锌在HE中所占的比例远大于NHE。叶和茎中磷(P)和硫(S)在HE中的分配模式与锌非常相似，而钙(Ca)的分配模式与锌相反。新植物学家(2009)182：116-126doi：10.1111/j.1469-8137.2008.02740.x。
Sedum alfredii is a fast-growing, high-biomass zinc (Zn) hyperaccumulator native to China. Here, the characteristics of in vivo Zn distribution in stems and leaves of the hyperaccumulating (HE) and nonhyperaccumulating ecotypes (NHE) of S. alfredii were investigated by synchrotron radiation X-ray fluorescence (SRXRF) analysis, together with a Zn probe.Preferential Zn accumulation in leaf and stem epidermis was observed in both ecotypes, but to a much greater extent for HE. Epidermal Zn increased largely in leaves and stems of HE as exposure time was prolonged, while Zn saturation occurred relatively early in HE leaf mesophyll cells and stem vascular bundles. A second peak of Zn enrichment in stem and leaf vascular systems was shown in both ecotypes. However, the proportion of Zn accumulated in stem vascular bundles relative to other tissues was much greater for HE than for NHE.Leaf and stem distribution patterns of phosphorus (P) and sulphur (S) in the HE were very like that for Zn, while the calcium (Ca) distribution pattern was the reverse of that for Zn. No such relationship was observed in NHE.Our study mainly suggested that epidermal layers serve as important storage sites for accumulated Zn in the S. alfredii HE.New Phytologist (2009) 182: 116-126doi: 10.1111/j.1469-8137.2008.02740.x.