Nanoparticles as nanofertilizer. Impact of magnetite nanoparticles on plant photosynthesis

TORRES ROCIO; LAGORIO, M. GABRIELA; VIRGINIA E. DIZ

Lima

Workshop; Worskhop Nanoandes 2020; 2021

RESUMEN Nanoparticles as nanofertilizer. Impact of magnetite nanoparticles on plant photosynthesis.Torres, Rocioa,b; Diz, Virginia E.b; Lagorio, M. Gabrielaa,ba)CONICET, Universidad de Buenos Aires, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentinab)Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Dpto. de Química Inorgánica, Analítica y Química Física, Ciudad Universitaria. Pabellón II, 1er piso, C1428EHA, Buenos Aires, Argentina.rtorres@qi.fcen.uba.arvdiz@qi.fcen.uba.armgl@qi.fcen.uba.arThe light energy absorbed by a leaf is collected and transferred to the reaction center of photosystem II (RC-PSII), where it can initiate the photosynthetic process, be dissipated as heat or be emitted as fluorescence. Therefore, the measurement of chlorophyll fluorescence provides information on photosynthesis and the physiological state of plants.1 At present, the potential action of nanoparticles in natural systems is relevant.2 In this work, the effect of magnetite nanoparticles on plants was evaluated, by studying the changes in the optical, spectroscopic and photochemical properties of leaves sprayed with dispersions of magnetite nanoparticles.Magnetite nanoparticles were synthesized according to Sun et al.3 and were characterized by SEM, TEM, FTIR, DRX and VSM. Nanoparticles of 10 ± 2 nm in diameter with high magnetization and purity were thus obtained. Leaves of A. hybridus were sprayed with suspensions of 0 (control), 10, 100 and 1000 ppm of nanoparticles. Subsequently, fluorescence spectra, reflectance spectra and variable chlorophyll fluorescence (OJIP transient and Kautsky kinetics)4 were recorded for 5-7 days. Tukey's ANOVA and HSD tests with p ≤ 0.05 were used to determine statistical differences between treatments.No changes were observed in the fluorescence ratio (F680/F730) for spectra corrected by light re-absorption processes. An increase in the concentration of total chlorophyll in the leaves treated with magnetite was observed.5 Additionally, quantum yields associated with the photosynthetic electron transport rate were improved after treatment (Fig. 1). At the highest magnetite concentration, the maximum quantum yield of PSII increased a 35% and the quantum yield of heat dissipation as non-photochemical quenching decreased 38% compared to control. A significant increase in the amount of active RC-PSII per antenna was also observed in the presence of magnetite. The observed changes were dependent on the concentration of nanoparticles. Fig. 1: Quantum yields and photosynthetic efficiencies of magnetite-treated leaves.In conclusion, the treatment with magnetite nanoparticles produced an increase in photosynthetic quantum and electronic transport yields. This was also manifested by the increase in the concentration of chlorophylls and the amount of active RC-PSII.References1.K. Maxwell, G. Johnson. J. Exp. Bot. 51 (2000) 659.2.A. Rastogi, M. Zivcak, et al., Front. Chem. 5 (2017) 78.3.Sun, S.; Zeng, H. J. Am. Chem. Soc. 124 (2002) 8204.4.H. Kalaji, G. Schansker, et al. Photosynth. Res. 122 (2014) 121-158.5.M. Jalali, F. Ghanati, et al. J. Agron. Crop Sci. 203 (2017) 593-602