In vivo localization of manganese in the hyperaccumulator Gossia bidwillii (Benth.) N.!Snow & Guymer (Myrtaceae) by cryo-SEM/EDAX
In vivo localization of manganese in the hyperaccumulator Gossia bidwillii (Benth.) N.!Snow & Guymer (Myrtaceae) by cryo-SEM/EDAX
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DOI：
10.1111/j.1365-3040.2006.01498.x
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发表时间：
2006-05-01
影响因子：
7.3
通讯作者：
Woodrow, IE
中科院分区：
文献类型：
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作者：
Fernando, DR;Batianoff, GN;Woodrow, IE
Gossia bidwillii（桃金娘科）是一种锰（Mn）超积累树，原产于亚热带澳大利亚东部。它通常含有超过1%干重的叶面锰水平。然而，在G. bidwillii和其他锰超积累物种，锰的细胞和亚细胞定位尚未测量。定量在体内冷冻扫描电子显微镜（SEM）/能量色散X射线分析（EDAX）被用来定位锰和其他元素的组织中收集的成熟树木生长在自然人口。扫描电镜观察表明，叶肉分化为海绵状叶肉之上的双层栅栏叶肉。透射电子显微镜（TEM）观察表明，栅栏和表皮细胞高度空泡化. EDAX数据被用来估计在原位液泡锰浓度的所有类型的细胞在新鲜的冷冻固定叶组织。液泡中Mn含量最高的是上层栅栏叶肉，平均值超过500 mm，而海绵叶肉中Mn含量最低，平均值在100 mm左右。定性在体内cryo-SEM/EDAX进一步研究了锰的空间分布在新鲜的叶组织和年轻的树皮组织，这也被发现有一个高的锰浓度。结果表明，Mn在G. bidwillii在数量上不同于其他超积累物种中的金属分布，在其他超积累物种中，这些元素的最高局部浓度出现在非光合组织中，例如表皮细胞和相关的真皮结构，包括毛状体和叶毛。
Gossia bidwillii (Myrtaceae) is a manganese (Mn)-hyperaccumulating tree native to subtropical eastern Australia. It typically contains foliar Mn levels in excess of 1% dry weight. However, in G. bidwillii and other Mn-hyperaccumulating species, the cellular and subcellular localization of Mn has not been measured. Quantitative in vivo cryo-scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDAX) was used to localize Mn and other elements in tissue collected from mature trees growing in a natural population. Cryo-SEM showed that the leaf mesophyll is differentiated as a double-layer palisade mesophyll above spongy mesophyll. Transmission 31 electron microscopy (TEM) revealed that the palisade and epidermal cells are highly vacuolated. EDAX data were used to estimate in situ vacuolar Mn concentrations of all cell types in fresh cryo-fixed leaf tissues. The highest average vacuolar Mn concentration of over 500 mm was found in the upper-layer palisade mesophyll, while the lowest concentration of around 100 mm was found in the spongy mesophyll. Qualitative in vivo cryo-SEM/EDAX was employed to further investigate the spatial distribution of Mn in fresh leaf tissues and young bark tissue, which was also found to have a high Mn concentration. It is concluded that Mn distribution in G. bidwillii is quantitatively different to metal distribution in other hyperaccumulating species where the highest localized concentrations of these elements occur in non-photosynthetic tissues such as epidermal cells and associated dermal structures including trichomes and leaf hairs.