China
Africa
Explore chapters and articles related to this topic
Agri-Applications of Nano-Scale Micronutrients
Published in Ramesh Raliya, Nanoscale Engineering in Agricultural Management, 2019
Iron (Fe) is an important component of several proteins involved in electron transport chains and functioning as anti-oxidant enzymes, such as the heme proteins (cytochromes and peroxidases), iron-sulfur proteins (ferrodoxin and superoxide dismutase) and iron-containing enzymes (lipoxygenase). The insolubility of the ferric (Fe3+) ionic form of iron is largely responsible for its scarcity in the soil solution, thus culminating to its very low plant-available form for uptake by the plant despite its abundance in various soils. In barley, application of nano Fe/SiO2 fertilizer at concentrations of 5, 15 and 25 mg kg−1 led to increase in shoot length over the conventional Fe/SiO2 fertilizer (Disfani et al. 2016). However, in the case of maize, enhanced shoot growth could only be observed at lower concentrations while it decreased at higher amount (25 mg kg−1) as compared to conventional Fe/SiO2 fertilizer. Continuous exposure of rice seeds to FeO nanoparticles (< 50 nm) at 100 ppm for 10 days helped to enhance the vegetative growth (shoot and root length and plant biomass), while at a higher concentration of 400 ppm, the FeO NPs led to an increase in total chlorophyll, total protein content, peroxidase and catalase activities in the leaves of the test plants (Mankad et al. 2017).
Applications and challenges of elemental sulfur, nanosulfur, polymeric sulfur, sulfur composites, and plasmonic nanostructures
Published in Critical Reviews in Environmental Science and Technology, 2019
Yong Teng, Qixing Zhou, Peng Gao
Iron-sulfur proteins are found in all life forms, and iron-sulfur clusters as their cofactors, are the oldest and most versatile inorganic cofactors with the function of catalysis, electron transfer, and sensing of iron and oxygen of ambient conditions (Beinert, Holm, & Münck, 1997; Lill, 2009). Fe2S2, Fe3S4, and Fe4S4 clusters containing iron (Fe2+/3+) and sulfide (S2−), and other metal ions for more complex clusters, are the frequent types of iron-sulfur clusters, and they may be inserted or removed from proteins through oxidation-reduction reactions (Beinert et al., 1997). The synthesis and assembly into apoproteins in living cells is complex and a coordinated process and the summarized common biosynthetic rules are as follows (Lill, 2009): (1) the de novo assembly of an Fe-S cluster on a scaffold protein, (2) the transfer of the Fe-S cluster from the scaffold to target apoproteins and its subsequent assembly into the polypeptide chain (Figure 4) (Beinert et al., 1997; Lill, 2009).