Search

The study aims at investigating the efficacy of individual as well as combined application of AM fungi (Glomus macrocarpum) and ZnO nanoparticles on the uptake of lead and its toxicity in wheat (Triticum aestivum L.). The plants were grown in pots with different treatments of AM Fungi, ZnO NP, and Pb. The individual applications of AM fungi (Glomus macrocarpum) and ZnO NPs increased the growth and biochemical attributes of wheat and decreased the Pb uptake under Pb stress. The combined application of AM fungi (Glomus macrocarpum) and ZnO nanoparticles synergistically enhanced the overall growth performance of the plant and significantly reduced the uptake of Pb in wheat grown in Pb spiked soils. The combined application was effective, with 30.66 % increase in plant height, 30.62 % increase in plant fresh weight, 54.26 % increase in plant dry weight, 45.45 % increase in total chlorophyll content, 19.59 % increase in proline content, 26.65 % higher activity of SOD, 15.12 % higher activity of catalase (CAT), 17.69 % increase in H2O2 content, 17.69 % increase in lipid peroxidation content, 52.09 % and 58.19 % decrease in Pb concentration in root and shoot of wheat, respectively, grown in Pb spiked soil (100 mg kg−1 soil). The results indicate that combined application of AM fungi and ZnO nanoparticles can be a promising technique for the utilization of Pb-contaminated soils.

Plant phenolics or polyphenols, the aromatic compounds with one or more hydroxyl groups, are produced by plants mainly for protection against stresses. Phenolics are secondary natural metabolites emerging from the shikimate/phenylpropanoid pathway or polyketide acetate/malonate pathway, producing monomeric and polymeric phenols and polyphenols, which participate in a wide range of physiological activities in plants. Plants are known to have synthesized thousands of different phenolic compounds throughout the course of evolution to cope with constantly changing environments. Plants accumulate phenolic compounds in their tissues as an adaptive response to adverse environmental conditions and have a key role in the regulation of various environmental stresses, such as high light, low temperatures, pathogen infection, herbivores, and nutrient deficiency. This chapter details the biosynthesis, role, and regulation of plant phenolics in response to various abiotic stresses.

Lead (Pb) contamination of agroecosystems is a serious issue as Pb is a persistent pollutant that is retained in soil for long, causing toxicities to organisms. This study examines biotransfer of Pb from soils treated with different concentrations of Pb through a broad bean (Vicia faba L.)–aphid (Aphis fabae Scop.)–ladybird (Coccinella transversalis Fabricius) food chain and its consequent inference for natural biological control, the ladybird. The soil was amended with Pb at the rates of 0, 25, 50, 75 and 100 mg kg−1 (w/w). The amount of Pb in plant, aphid and ladybird increased in a dose-dependent manner to Pb contents in the soil. The results showed that Pb biomagnified from soil to root with transfer coefficient always > 1. Biominimization of Pb occurred at the second trophic level in aphids and at the third trophic level in ladybirds as their respective transfer coefficients from shoot to aphid and aphid to ladybird were always