Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane, QLD, Australia.
Laboratory of Genetics, Wageningen University and Research, Wageningen, The Netherlands.
Planta. 2023 Jul 9;258(2):41. doi: 10.1007/s00425-023-04167-3.
The VNIR reflectance spectra of nickel hyperaccumulator plant leaves have spectral variations due to high nickel concentrations and this property could potentially be used for discovery of these plants. Hyperaccumulator plants accumulate high concentrations of certain metals, including manganese, cobalt, or nickel. Of these metals, the divalent ions of nickel have three absorption bands in the visible to near-infrared region which may cause variations in the spectral reflectance of nickel hyperaccumulator plant leaves, but this has not been investigated previously. In this shortproof-of-concept study, the spectral reflectance of eight different nickel hyperaccumulator plant species leaves were subjected to visible and near-infrared and shortwave infrared (VNIR-SWIR) reflectance spectrum measurements in dehydrated state, and for one species, it was also assessed in hydrated state. Nickel concentrations in the plant leaves were determined with other methods and then correlated to the spectral reflectance data. Spectral variations centred at 1000 ± 150 nm were observed and had R-values varying from 0.46 to 0.96 with nickel concentrations. The extremely high nickel concentrations in nickel hyperaccumulator leaves reshape their spectral reflectance features, and the electronic transition of nickel-ions directly contributes to absorption at ~ 1000 nm. Given that spectral variations are correlated with nickel concentrations it make VNIR-SWIR reflectance spectrometry a potential promising technique for discovery of hyperaccumulator plants, not only in the laboratory or herbarium, but also in the field using drone-based platforms. This is a preliminary study which we hope will instigate further detailed research on this topic to validate the findings and to explore possible applications.
镍超积累植物叶片的可见近红外（VNIR）反射光谱由于镍浓度高而存在光谱变化，这一特性可能用于发现这些植物。超积累植物会积累高浓度的某些金属，包括锰、钴或镍。在这些金属中，镍的二价离子在可见到近红外区域有三个吸收带，这可能导致镍超积累植物叶片的光谱反射率发生变化，但这一点以前尚未得到研究。在这项初步概念验证研究中，对八种不同镍超积累植物叶片的光谱反射率进行了可见近红外和短波红外（VNIR-SWIR）反射光谱测量，在脱水状态下进行，对其中一种植物也在水合状态下进行了评估。使用其他方法测定了植物叶片中的镍浓度，然后将其与光谱反射率数据相关联。观察到以 1000 ± 150nm 为中心的光谱变化，镍浓度的 R 值从 0.46 到 0.96 不等。镍超积累叶片中极高的镍浓度重塑了它们的光谱反射特征，镍离子的电子跃迁直接导致了在~1000nm 的吸收。鉴于光谱变化与镍浓度相关，VNIR-SWIR 反射光谱法成为发现超积累植物的一种有潜力的有前途的技术，不仅在实验室或标本馆中，而且在使用基于无人机的平台的野外也可以使用。这是一项初步研究，我们希望它将进一步激发对这一主题的详细研究，以验证研究结果并探索可能的应用。
