Role of Bio-Based Synthesized Nanozinc Oxide in Ameliorating the Deleterious Effects Caused by Lead in Vigna radiata L.

The present work describes the bio-based green synthesis and characterization of zinc oxide nanoparticles (ZnO NPs) using leaf extract of Tridax procumbens; the synthesized nanoparticles were used to study their beneficial effect on the growth and metabolism of Vigna radiata. ZnO NPs were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and ultraviolet-visible spectroscopy (UV-Vis spectra). Growth of V. radiata seedlings was measured in terms of shoot length and root length that were treated 20 and 40 mg/L concentrations of green synthesized ZnO NPs and constant concentration (50 mg/L) of PbCl2. These studies have shown the effect of ZnO NPs in the stimulation of growth as well as physiological and biochemical parameters. Vigna seedlings showed positive effects depending upon the increasing concentrations of ZnO NPs. This study suggests that ZnO NPs can be effectively used to ameliorate the toxicity of Pb in Vigna plants.

Phytochemicals mitigation of Brassica napus by IAA grown under Cd and Pb toxicity and its impact on growth responses of Anagallis arvensis.

Beginning of industrialization accelerates the heavy metal pollution in the biosphere. Plant being the immovable entity utilizes different mechanisms to flee from unfavourable conditions. To alleviate toxic impact of metals like cadmium (Cd) and lead (Pb), phytohormones such as indole acetic acid (IAA) has been applied exogenously. This manuscript aims to evaluate the significant change occurring in biochemical parameters of Indian mustard (Brassica napus) grown under individual and combined treatments of IAA with Cd and Pb. Herbicidal potential of treated Brassica extracts were evaluated on growth and development of Anagallis arvensis. Quantum yield parameters were more sensitive to Cd than Pb stress resulted in reduced photosynthetic pigments. However, exogenously applied IAA together with Cd and Pb considerably improved the level of photosynthetic attributes along with reduced accumulation of Cd and Pb in Brassica plant. Cd and Pb enhanced the activities of reactive oxygen species (ROS) and antioxidant machinery. However, addition of IAA with Cd and Pb mitigated the effect of heavy metals on antioxidant system. Moreover, activity of the phenylalanine ammonia lyase enzyme and the defensive metabolites (phenolic, flavonoid and anthocyanin compounds) were boosted under individual treatments of Cd and Pb responsible for increasing herbicidal potential of Brassica plant. Our results exhibited essentiality of IAA in mitigating Cd and Pb stress in Brassica through up-regulated mechanisms of the antioxidant system for balancing ROS related injuries. Increased metabolites enhancing herbicidal potential of Brassica napus against Anagallis weed were also observed.