Maize ( Zea mays) is one of the most cultivated plants in the world. Due to the large area, the scale of its production, and the demand to increase the yield, there is a need for new environmentally friendly fertilizers. One group of such candidates is bacteria-produced nodulation (or nod) factors. Limited research has explored the impact of nodulation, factors on maize within field conditions, with most studies restricted to greenhouse settings and early developmental stages. Additionally, there is a scarcity of investigations that elucidate the metabolic alterations in the maize stem due to nod-factor exposure. It was therefore the aim of this study. Maize stem's metabolites and fibers were analyzed with various imaging analytical techniques: matrix assisted laser desorption ionization–mass spectrometry imaging (MALDI-MSI), Raman spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), and diffuse reflectance infrared Fourier transform spectroscopy. Moreover, the biochemical analyses were used to evaluate the proteins and soluble carbohydrates concentration and total phenolic content. These techniques were used to evaluate the influence of nod factor-based biofertilizer on the growth of a non-symbiotic plant, maize. The biofertilizer increased the grain yield and the stem mass. Moreover, the spectroscopic and biochemical investigation proved the appreciable biochemical changes in the stems of the maize in biofertilizer-treated plants. Noticeable changes were found in the spatial distribution and the increase in the concentration of flavonoids such as maysin, quercetin, and rutin. Moreover, the concentration of cell wall components (fibers) increased. Furthermore, it was shown that the use of untargeted analyses (such as Raman and ATR FT-IR, spectroscopic imaging, and MALDI-MSI) is useful for the investigation of the biochemical changes in plants.

中文翻译：

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评估基于 Nod 因子的肥料对玉米 (Zea mays) 茎的影响的多模态光谱研究

玉米（Zea mays）是世界上栽培最多的植物之一。由于其面积大、生产规模大、产量要求高，因此需要新型环保肥料。其中一组候选因子是细菌产生的结瘤（或结瘤）因子。有限的研究探讨了田间条件下结瘤因素对玉米的影响，大多数研究仅限于温室环境和早期发育阶段。此外，缺乏阐明由于点头因子暴露而导致的玉米茎代谢变化的研究。因此，这就是本研究的目的。使用各种成像分析技术对玉米茎的代谢物和纤维进行分析：基质辅助激光解吸电离质谱成像 (MALDI-MSI)、拉曼光谱、衰减全反射傅里叶变换红外光谱 (ATR FT-IR) 和漫反射红外傅里叶变换光谱。此外，生化分析用于评估蛋白质和可溶性碳水化合物的浓度以及总酚含量。这些技术用于评估基于点头因子的生物肥料对非共生植物玉米生长的影响。生物肥料增加了谷物产量和茎质量。此外，光谱和生化研究证明，在生物肥料处理的植物中，玉米茎发生了明显的生化变化。黄酮类化合物如蛋黄素、槲皮素和芦丁的空间分布和浓度增加发生了明显的变化。此外，细胞壁成分（纤维）的浓度增加。此外，研究表明，使用非靶向分析（例如拉曼和 ATR FT-IR、光谱成像和 MALDI-MSI）对于研究植物的生化变化非常有用。