Zinc deficiency in cucumber plants can be alleviated by fullerenol

Abstract

Zinc (Zn) deficiency is one of the most limiting factors in plant growth and productivity worldwide. Among carbon-based nanomaterials, water-soluble fullerene derivates offer unique opportunities to increase crop productivity and protection. In this work, we evaluated the stress mitigation effects of fullerenol in cucumber plants (Cucumis sativus L.) submitted to Zn deficiency conditions. Cucumber plants were grown hydroponically, either with (+Zn) or without (−Zn) a Zn supply, with (+F) or without (−F) a fullerenol supply. Fullerenol was added in a nutrient solution either before the beginning of Zn deficiency (plant priming) or at its start. A nutrient imbalance, leaf yellowing and spotting, a reduced electron transport rate (ETR), enhanced oxidative damage by excessive production of malondialdehyde (MDA) and retarded plant growth were found in Zn-deficient plants. After fullerenol treatment, some symptoms of Zn deficiency were alleviated. Overall, fullerenol decreased leaf MDA and spotting (visual observations). When fullerenol was added in a Zn-free solution, plants exhibited enhanced leaf chlorophyll or shoot dry biomass compared with non-treated plants. Also, an increase in xylem sap or young leaf Zn was observed in fullerenol-treated plants under Zn deficiency. With the exception of the MDA responses and spotting, these effects appear to occur in a dose-dependent manner. In contrast, the Zn-fed plants remained phenotypically unaffected by fullerenol. Thus, fullerenol probably alleviated Zn deficiency due to an improvement in Zn remobilization and the antioxidant capacity of the plants, in turn decreasing lipid peroxidation.