Combined passivators regulate physiological, antioxidant potential and metals accumulation in potato grown in metals contaminated soil.

To solve the problem of excessive heavy metals in farmland soil, there is a dire need for research effort to screen for the soil passivator materials. This study aimed to develop a practical novel approach for improving the potato growth and remedial effectiveness of the metals by optimal combination and dosage of various passivators. Experimental treatments were comprised of various levels of passivating agents (sepiolite, quicklime and calcium magnesium phosphate) in individual and combined form. Results showed that application of passivating agents significantly enhanced growth by optimizing photosynthetic attributes, enzymatic antioxidants, and soil health. Balanced application of passivators effectively reduce the bioavailability of metals, curbing their uptake by potato plants. Sole application of all the agents results statistically similar outcomes as compared with combined form. Additionally, passivators indirectly enhance the activity of essential antioxidant enzymes. Synergistic effect of all the agents significantly improved the tuber quality by decreasing the accumulation of proline, malondialdehyde content, and bioaccumulation of Cu, Pb, Cd, and As in potato parts. In crux, combined usage of passivating agents proved to be of better growth, improvement in antioxidative defense system, and better quality of potato. By mitigating heavy metal contamination, passivators not only enhance crop quality and yield but also ensure heavy metal-free potatoes that meet stringent food safety standards.

Alleviation of Cadmium Stress by Silicon Supplementation in Peas by the Modulation of Morpho-Physio-Biochemical Variables and Health Risk Assessment.

Agricultural soil quality degradation by potentially toxic elements, specifically cadmium (Cd), poses a significant threat to plant growth and the health of humans. However, the supplementation of various salts of silicon (Si) to mitigate the adverse effect of Cd on the productivity of peas (Pisum sativum L.) is less known. Therefore, the present investigation was designed to evaluate the exogenous application at various levels (0, 0.50, 1.00 and 1.50 mM) of silicate compounds (sodium and potassium silicates) on pea growth, gaseous exchange, antioxidant enzyme activities and the potential health risk of Cd stress (20 mg kg-1 of soil) using CdCl2. The findings of the study showed that Cd stress significantly reduced growth, the fresh and dry biomass of roots and shoots and chlorophyll content. In addition, electrolyte leakage, antioxidant enzymes and the content of Cd in plant tissues were enhanced in Cd-induced stressed plants. An application of Si enhanced the development of stressed plants by modulating the growth of fresh and dry biomass, improving the chlorophyll contents and decreasing leakage from the plasma membrane. Furthermore, Si addition performed a vital function in relieving the effects of Cd stress by stimulating antioxidant potential. Hence, a significant level of metal protection was achieved by 1.00 mM of potassium silicate application under the Cd levels related to stress conditions, pointing to the fact that the Si concentration required for plant growth under Cd stress surpassed that which was required for general growth, enzymatic antioxidants regulation and limiting toxic metal uptake in plant tissues under normal conditions. The findings of this research work provide a feasible approach to reduce Cd toxicity in peas and to manage the entry and accumulation of Cd in food crops.

Silicon fertilization counteracts salinity-induced damages associated with changes in physio-biochemical modulations in spinach.

Plant growth and productivity are limited by the severe impact of salt stress on the fundamental physiological processes. Silicon (Si) supplementation is one of the promising techniques to improve the resilience of plants under salt stress. This study deals with the response of exogenous Si applications (0, 2, 4, and 6 mM) on growth, gaseous exchange, ion homeostasis and antioxidant enzyme activities in spinach grown under saline conditions (150 mM NaCl). Salinity stress markedly reduced the growth, physiological, biochemical, water availability, photosynthesis, enzymatic antioxidants, and ionic status in spinach leaves. Salt stress significantly enhanced leaf Na+ contents in spinach plants. Supplementary foliar application of Si (4 mM) alleviated salt toxicity, by modulating the physiological and photosynthetic attributes and decreasing electrolyte leakage, and activities of SOD, POD and CAT. Moreover, Si-induced mitigation of salt stress was due to the depreciation in Na+/K+ ratio, Na+ ion uptake at the surface of spinach roots, and translocation in plant tissues, thereby reducing the Na+ ion accumulation. Foliar applied Si (4 mM) ameliorates ionic toxicity by decreasing Na+ uptake. Overall, the results illustrate that foliar applied Si induced resistance against salinity stress in spinach by regulating the physiology, antioxidant metabolism, and ionic homeostasis. We advocate that exogenous Si supplementation is a practical approach that will allow spinach plants to recover from salt toxicity.