Effects of fullerene C60 on the uptake of nitrogen and mineral elements in crops using synchrotron radiation micro-X-ray fluorescence spectrometry (SR-μXRF) and stable isotope labelling

Abstract

The unique characteristics of fullerene (C₆₀) have attracted great attention in the agricultural field. However, its potential effects on nitrogen sources and the uptake of various mineral nutrients required for plant growth remain unclear. In this study, we take advantage of the stable isotope ¹⁵N labeling technique combined with synchrotron radiation micro-X-ray fluorescence spectrometry (SR-μXRF) to investigate efficiently the effects of C₆₀ (70–200 nm) on the uptake level of nitrogen and multiple mineral elements in three common crops (maize, wheat, and soybean). The results showed that C₆₀ had different effects on the uptake of nitrogen and 15 mineral elements in different types of crops. C₆₀ significantly decreased the uptake rate of nitrate nitrogen in maize and soybean by 52.4% and 66.1%, respectively, but it had no significant effects on the uptake of ammonium nitrogen. In contrast, C₆₀ had no significant effect on the uptake of nitrate nitrogen in wheat, but it significantly increased the uptake rate of ammonium nitrogen by more than 3-fold. In addition, C₆₀ tended to change the uptake of 15 mineral elements in wheat, maize and soybean, but significant differences were found only in the uptake of K, Ca and Fe in different tissues of three crops. Our results suggest that the joint analysis technology not only facilitates the simultaneous comparison of the uptake of total mineral nutrients (including organic and inorganic nutrients) in plants but also enables us to obtain the impact of nanomaterials on plant growth. C₆₀ can improve the uptake of nitrogen and change mineral elements in crops, possibly avoiding damage to soils and the environment caused by the overuse of fertilizers and increasing the yield quantity and quality of crops.