van Maarschalkerweerd Marie, Bro Rasmus, Egebo Max, Husted Søren
Department of Plant and Environmental Sciences, University of Copenhagen , Thorvaldsensvej 40, Frederiksberg C, Denmark.
J Agric Food Chem. 2013 Nov 20;61(46):10901-10. doi: 10.1021/jf402166g. Epub 2013 Nov 11.
Chemometric analysis of near-infrared (NIR) spectra recorded directly on fresh leaves of barley plants (Hordeum vulgare, L.) enabled the separation of control and Cu deficient samples before any visual deficiency symptoms developed. This demonstrates that the molecular structure of leaves is modified during latent Cu deficiency. Lignin biosynthesis is a primary target of Cu deficiency, but lignin concentrations were unaltered when separation was first possible, indicating that alteration of lignin composition, not concentration, is among the earliest effects of Cu deficiency in plants. Validation of chemometric models using an independent test set found that 92% of samples were correctly classified as control or Cu deficient, respectively. Models were undisturbed by including spectra from plants deficient in P, Mg, B, or Mn, establishing their specificity for Cu deficiency. This study is the first to demonstrate that NIR has the potential to successfully diagnose the deficiency of an essential trace element in plants.
对直接记录在大麦植株（大麦属，L.）新鲜叶片上的近红外（NIR）光谱进行化学计量学分析，能够在任何视觉上的缺素症状出现之前，将对照样本和缺铜样本区分开来。这表明在潜在缺铜期间，叶片的分子结构发生了改变。木质素生物合成是缺铜的主要靶点，但在首次能够区分时，木质素浓度并未改变，这表明木质素组成的改变而非浓度的改变是植物缺铜最早产生的影响之一。使用独立测试集对化学计量学模型进行验证发现，92%的样本被正确分别归类为对照或缺铜样本。通过纳入磷、镁、硼或锰缺乏的植物光谱，模型并未受到干扰，从而确立了其对缺铜的特异性。本研究首次证明近红外有潜力成功诊断植物中必需微量元素的缺乏情况。
