Fullerenol increases effectiveness of foliar iron fertilization in iron-deficient cucumber

Abstract

The water-soluble fullerenols are novel carbon-based nanomaterials with unique properties, which afford them with wide agricultural applications. Iron (Fe) deficiency is the most common and widespread nutrition disorder affecting plants. Foliar Fe treatments of plants have been carried out with solutions devoid of fullerenol. In this study, the role of fullerenol [C 60 (OH) 22-24 ] in alleviation of Fe deficiency in Cucumis sativus (a Strategy I plant) via foliar fertilization was investigated. Cucumber plants were grown hydroponically, either with (Fe) or in Fe-free (−Fe) nutrient solution. The following foliar spray treatments were applied: fullerenol at final concentrations of 1 (F1) and 10 (F10) mg L-1 ; Fe(II)SO 4 ·7H 2 O; Fe(II)-EDTA (ethylenediaminetetraacetic acid); and Fe(II)-F1 and Fe(II)-F10. The best used compound was a combination of Fe(II)-sulfate with fullerenol, especially Fe-F1. The addition of fullerenol to Fe(II)-sulfate solutions significantly increased leaf-active Fe (extracted by an Fe(II) chelator) and re-greening at the site of application. The fullerenol-induced mutual influences did not appear when fullerenol was sprayed alone, suggesting a beneficial role of Fe(II)-fullerenol interactions in the penetration of Fe(II) in the leaves and re-greening under Fe-limited conditions. The results are of importance to enhancing the potential of foliar Fe fertilization as the commonly used strategy for ameliorating Fe deficiency and improving crop yield and quality.

Fullerenol changes metabolite responses differently depending on the iron status of cucumber plants

“…Polyhydroxylated fullerene C 60 (OH) 22–24 was synthesised and identified using previously developed methods, as described recently [ 21 , 36 , 37 ]. The identification of the obtained sample was performed utilising IR spectroscopy, elemental analysis, size distribution, and ζ -potentials study.…”

“…From the results of elemental analysis, a relative molar weight of 1128 g mol –1 , corresponding to the C 60 (OH) 24 formula, was applied in all further calculations. Size distribution revealed that the hydrodynamic diameters of fullerenol nanoparticles in the binary C 60 (OH) 22–24 –H 2 O system were 21 nm, and ζ -potentials values were −30 mV; therefore, indicating that even at low concentrations ( C = 1 mg L -1 ), fullerenol forms associates in aqueous solution and the solutions are electrokinetically stable [ 21 ].…”

“…In addition, fullerenol stimulated hypocotyl elongation in Arabidopsis [ 19 ]. Foliar application of fullerenol alleviated drought impact in sugar beets and Fe chlorosis in cucumber [ 20 , 21 ]. Very recently, we found that fullerenol could protect cucumber plants against Fe deficiency through increased utilisation of root apoplastic Fe [ 22 ].…”

Effects of Soil Aeration and Fertilization Practices on Alleviating Iron Deficiency Chlorosis in “Huangguan” Pears Grafted onto Quince A in Calcareous Soils

“…This result indicated that the Fe added to the leaves by spraying may have been deposited in the apoplast as inactive Fe. However, recently, the addition of fullerenol to Fe(II)-sulfate sprays has been shown to increase leaf active Fe and successfully suppress Fe deficiency symptoms by increasing the stability of the applied Fe(II) [51]; increasing Fe(II) stability is important for enhancing the potential of foliar Fe fertilization.…”

“…Many studies have also shown that some practices can indirectly promote Fe uptake by plants [19,20]. Conventional tillage (soil plowing at 20 cm) significantly increases Fe accumulation in peanuts by 51.2% compared with that under no tillage [21]. Short, highfrequency irrigation periods alleviate leaf chlorosis in apple and pear trees in calcareous soils with a caliche layer [22].…”