Comparative assessment of pantothenic, aspartic, ascorbic and tartaric acids assisted Pb-phytoextraction by sunflower (Helianthus annuus L.).

Phytoextraction of lead (Pb) is a challenging task due to its extremely low mobility within soil and plant systems. In this study, we tested the influence of some novel chelating agents for Pb-phytoextraction using sunflower. The Pb was applied at control (0.0278 mM) and 4.826 mM Pb as Pb(NO3)2 through soil-spiking. After 10 days of Pb addition, four different organic ligands (aspartic, ascorbic, tartaric, and pantothenic acids) were added to the soil at 1 mM concentration each. respectively. In the absence of any chelate, sunflower plants grown at 4.826 mM Pb level accumulated Pb concentrations up to 104 µg g-1 DW in roots, whereas 64 µg g-1 DW in shoot. By contrast, tartaric acid promoted significantly Pb accumulation in roots (191 µg g-1 DW; + 45.5%) and shoot (131.6 µg g-1 DW; + 51.3%). Pantothenic acid also resulted in a significant Pb-uptake in the sunflower shoots (123 µg g-1 DW; + 47.9%) and in roots (177.3 µg g-1 DW; + 41.3%). The least effective amongst the chelates tested was aspartic acid, but it still contributed to + 40.1% more Pb accumulation in the sunflower root and shoots. In addition, plant growth, biochemical, and ionomic parameters were positively regulated by the organic chelates used. Especially, an increase in leaf Ca, P, and S was evident in Pb-stressed plants in response to chelates. These results highlight that the use of biocompatible organic chelates positively alters plant physio-biochemical traits contributing to higher Pb-sequestration in sunflower plant parts.

Correction to "Mitigation of Salinity Stress and Lead Toxicity in Maize by Exogenous Application of the Sorghum Water Extract".

[This corrects the article DOI: 10.1021/acsomega.3c09495.].

Mitigation of Salinity Stress and Lead Toxicity in Maize by Exogenous Application of the Sorghum Water Extract.

The increased concentration of lead (Pb) in soils is a serious threat to human beings and plants all over the world. Salinity stress is also a major issue across the globe, which limits crop productivity. The use of allelochemicals has become an effective strategy to mitigate the toxic effects of abiotic stresses. Sorghum is an important crop grown across the globe, and it also possesses an appreciably allelopathic potential. Therefore, this study was planned to determine the impacts of the sorghum water extract (SWE) on improving maize growth under Pb and salinity stress. The experiment included different treatments; control, SWE (3%), and different levels of Pb and salinity stress; T1: control, T2: 50 mM NaCl, T3: 100 mM NaCl, T4: 250 µM Pb, and T5: 500 µM Pb. Lead and salinity stress reduced the maize growth by the genesis of reactive oxygen species (ROS), as evidenced by higher production of malondialdehyde (MDA: 39.1 and 32.28%) and hydrogen peroxide (H2O2: 20.62 and 17.81%). Spraying plants with SWE improved the maize growth by increasing antioxidant activities (ascorbate peroxidase: APX, catalase: CAT, peroxidase: POD and superoxide dismutase: SOD), photosynthetic pigments, relative water contents (RWC), osmolyte accumulation (proline, total soluble proteins: TSP, free amino acids: FAA), potassium accumulation, and decreasing MDA, H2O2, sodium, chloride, and Pb accumulation. In conclusion, the application of SWE mitigates adverse impacts of Pb and salinity stresses by improving chlorophyll synthesis and osmolyte accumulation, activating the antioxidant defense system, and preventing the entry of toxic ions.