Copper oxide nanomaterials as possible nanofertilizers in zucchini plants

The worldwide grain production faces many challenges to keep up with the steady growth of the global demand. Today the productivity of crops is based on the application of high amounts of industrially produced nitrogen (N) fertilizer, even though crop plants utilize only 30-40% of the applied N. This implies of course an excessive use of chemical fertilizers with a consequent negative impact on the environment and on farmer economies.
The continuous search for innovative solutions has brought the attention to novel nanomaterials. Nanofertilizers are among the most promising engineered materials currently tested, both for soil and foliar applications. It is expected that properly designed nanostructures could allow controlled release of nutrients, exactly synchronizing it with the nutritional needs of the crops, thus avoiding nutrients loss.
Encouraging results have been already obtained using nanofertilizers in different plant species.
In particular, the present study, led by the Department of Chemistry, Life Sciences and Environmental Sustainability at the University of Parma (Italy), aimed at characterizing the response in Cucurbita pepo L. (zucchini) upon exposure to a potential nanoscale fertilizer: copper oxide (CuO) nanoparticles. The plant response to such nanomaterials exposure was investigated from a morphological, physiological, molecular, and atomic perspective and was also compared with conventional copper bulk and salt forms (CuSO4).
The exposed specimens were firstly investigated with conventional laboratory techniques, global transcriptomic approach (by RNA-seq) and SEM-EDX microscopy and then with synchrotron-based analyses in Elettra, specifically µ-XRF at TwinMic and XANES at X-ray Fluorescence beamline. Bulk X-ray Absorption Spectroscopy (XAS) analyses were also carried out at BM08 “LISA” beamline at ESRF synchrotron (Grenoble, France).
µ-XRF analyses performed at the TwinMic beamline at 1.35 µm resolutions, an example of which is depicted in Figure 1a, showed that in the root sections, Cu was in general mainly detectable on cell walls and more visible in the treatments with CuSO4; the higher presence of Cu in the treatments with CuSO4is due to the salt dissociation in the soil and followed by ready Cu accumulation in the roots.
The XANES measurements performed at X-ray Fluorescence beamline of Elettra (Figure 1b) showed that in treatment with CuSO4salt the Cu valence in samples was prevalently maintained as ionic (Cu2+), as confirmed also by XANES and EXAFS analyses at LISA in ESRF.
The synchrotron results, combined with the overall findings, show that Cu local structure changes upon nano-CuO internalization, hinting at potential nanoparticles biotransformation within the plant tissues. Therefore, this suggests that the use of nanoscale CuO NPs as nanofertilizers likely presents minimal concerns to general plant health.
Nano-CuO uniquely stimulates the plant response in a way that can minimize agrochemical effects to the environment, and therefore could be an important strategy in nano-enabled agriculture.



Figure 1.   a) Low energy μ-XRF maps of roots from zucchini plants treated with CuO NPs, depicted with their corresponding absorption image (Abs). Names of the mapped elements are on top of each figure. Scale bar is 10 μm. b) XANES spectrum of roots from zucchini plants treated with CuO NPs (blue line), linear combination fit (red line) with its Fe compounds contributions.


This research was conducted by the following research team:

Marta Marmiroli1, Luca Pagano1, Riccardo Rossi1, Roberto De La Torre-Roche2, Giovanni Orazio Lepore3, Roberta Ruotolo1, Gianluca Gariani4, Valentina Bonanni4, Simone Pollastri4, Alessandro Puri5, Alessandra Gianoncelli4, Giuliana Aquilanti4, Francesco d’Acapito5, Jason C. White2, Nelson Marmiroli1,6


Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy. 
The Connecticut Agricultural Experiment Station, New Haven, CT, USA. 
Earth Science Department, University of Florence, Firenze, Italy.
Elettra - Sincrotrone Trieste S.C.p.A., Trieste, Italy
CNR-IOM-OGG c/o ESRF – The European Synchrotron, Grenoble Cédex 9, France.
Consorzio Interuniversitario Nazionale per le Scienze Ambientali (CINSA), University of Parma, Parma, Italy.

Contact persons:

Marta Marmiroli, 
Alessandra Gianoncelli,
Giuliana Aquilanti,



Marta Marmiroli, Luca Pagano, Riccardo Rossi, Roberto De La Torre-Roche, Giovanni Orazio Lepore, Roberta Ruotolo, Gianluca Gariani, Valentina Bonanni, Simone Pollastri, Alessandro Puri, Alessandra Gianoncelli, Giuliana Aquilanti, Francesco d’Acapito, Jason C. White, Nelson Marmiroli "Copper Oxide nanomaterial fate in plant tissue: Nanoscale impacts on reproductive tissues", Environmental Science and Technology, (2021); DOI: 10.1021/acs.est.1c01123

Last Updated on Wednesday, 11 August 2021 15:19