Characterization of foliar manganese (Mn) in Mn (hyper)accumulators using X-ray absorption spectroscopy
Characterization of foliar manganese (Mn) in Mn (hyper)accumulators using X-ray absorption spectroscopy
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DOI：
10.1111/j.1469-8137.2010.03431.x
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发表时间：
2010-01-01
期刊：
影响因子：
9.4
通讯作者：
Collins, R. N.
中科院分区：
文献类型：
--
作者：
Fernando, D. R.;Mizuno, T.;Collins, R. N.
P>植物对必需营养物锰 (Mn) 的超富集是一种罕见现象，在西太平洋地区最为明显，与其他元素的超富集不同。锰超富集植物采用多种与物种相关的空间分布模式来封存过量的叶面锰，包括在非光合组织和光合组织中的初级封存。本研究采用同步加速器 X 射线吸收光谱 (XAS) 来对锰进行比较研究（超）蓄积剂，以原位阐明来自澳大利亚、新喀里多尼亚和日本的七种木本植物中叶面锰的化学形式。在所有样品中，叶面锰均以 Mn(II) 形式为主，强有力的证据表明苹果酸或柠檬酸等羧酸作为络合配体的作用。总体而言，X 射线吸收近边光谱 (XANES) 和扩展 X 射线吸收精细结构光谱 (EXAFS) 数据似乎与之前的观察结果相权衡，即草酸盐与 Mn（超）积累物质中过量的 Mn 结合。
P>Plant hyperaccumulation of the essential nutrient manganese (Mn) is a rare phenomenon most evident in the Western Pacific region, and differs from hyperaccumulation of other elements.Mn hyperaccumulators employ a variety of species-dependent spatial distribution patterns in sequestering excess foliar Mn, including primary sequestration in both nonphotosynthetic and photosynthetic tissues.This investigation employed synchrotron X-ray absorption spectroscopy (XAS) in a comparative study of Mn (hyper)accumulators, to elucidate in situ the chemical form(s) of foliar Mn in seven woody species from Australia, New Caledonia and Japan.Foliar Mn was found to predominate as Mn(II) in all samples, with strong evidence of the role of carboxylic acids, such as malate or citrate, as complexing ligands. Overall, the X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine-structure spectroscopy (EXAFS) data appeared weighted against previous observations that oxalate binds excess Mn in Mn-(hyper)accumulating species.