Physiological and biochemical characterization of Kalongi (Nigella sativa) against arsenic stress: Implications for human health risk assessment

• Published in: Environmental pollution (1987) 2022-04, Vol.298, p.118829-118829, Article 118829
• Main Authors: Shamshir, Farwah, Abbas, Ghulam, Amjad, Muhammad, Rizwan, Muhammad, Akram, Muhammad, Ahmad, Sajjad, Tahir, Muhammad, Ali, Shafaqat, Farooq, Abu Bakr Umer
• Format: Article
• Language: English
• Subjects: Antioxidants; Antioxidants - metabolism; Arsenic; Arsenic - toxicity; Humans; Hydrogen Peroxide; Lipid Peroxidation; MDA; Nigella sativa; Nigella sativa - metabolism; Risk Assessment; ROS; Soil Pollutants - analysis; Soil Pollutants - toxicity
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.118829

Arsenic (As) is a toxic metalloid that exhibits a varying degree of toxicity in plants depending upon the redox status of its species. Elemental arsenic [As(0)] is the least toxic of all the As species, however, under conducive environmental conditions, it can be readily oxidized into toxic forms. The present experiment was designed to evaluate the deleterious effects of As when applied in As(0) form on the morpho-physiological attributes of Kalongi (Nigella sativa). Seeds of N. sativa were sown in soil contaminated with various levels of As (0, 1.875, 3.75, 7.5, 15.0, and 30.0 mg nA(0) kg−1 soil). The results indicated that plant biomass and grain yield of N. sativa were not much affected by various levels of As except at 30 mg nA(0) kg−1 soil. Activities of antioxidant enzymes (SOD, APX, POX, and CAT), phenolic contents, and carotenoids were enhanced in response to the overproduction of H2O2, subsequently inhibiting lipid peroxidation. Arsenic accumulation in different plant organs increased with increasing soil As levels in the given trend root > shoot > leaf > seedpod > seed. Arsenic uptake affected the uptake of other elements (P, Fe, Zn, K, Na, Ca). Adaptive changes in total chlorophyll contents, MDA contents, and antioxidant enzymatic defense mechanism in response to As stress suggest that the N. sativa is tolerant to moderate As stress. Therefore, this crop can be cultivated on moderately As-contaminated soils without any significant risks of economic losses and food chain contamination. •Tolerance and physiological response of N. sativa under arsenic stress were studied.•Antioxidant enzymes, phenolic contents and ROS were enhanced under As stress.•As exposure significantly altered the uptake of other elements (P, Fe, Zn, Ca, K,).•Physiological parameters suggest that N. sativa is tolerant to moderate As stress.•N. sativa can be cultivated on As-contaminated soils and is safe for human use.