Biochar enhances the cadmium tolerance in spinach (Spinacia oleracea) through modification of Cd uptake and physiological and biochemical attributes

Abstract

Cadmium (Cd) has no known role in plant biology and is toxic to plants and animals. The Cd mainly accumulated in agricultural soils through anthropogenic activities, such as sewage water irrigation and phosphorus fertilization. Biochar (BC) has been proposed as an amendment to reduce metal toxicity in plants. The objective of this study was to evaluate the role of BC (cotton stick at a rate of 0, 3, and 5 %) on Cd uptake and the photosynthetic, physiological, and biochemical responses of spinach (Spinacia oleracea) grown in Cd-spiked soil (0, 25, 50, 75, and 100 mg Cd kg soil). The results showed that Cd toxicity decreased growth, photosynthetic pigments, gas exchange characteristics, and amino acid and protein contents in 52-day-old spinach seedlings. The Cd treatments increased the concentrations of Cd, sugar, ascorbic acid, and malondialdehyde (MDA) in plants. The application of BC ameliorated the harmful effects of Cd in spinach plants. Under Cd stress, BC application increased the growth, photosynthesis, and protein contents and decreased Cd concentrations and MDA contents in plants. The maximum BC-mediated increase in dry biomass was about 25 % with 5 % BC application in control plants. It is concluded that BC could ameliorate Cd toxic effects in spinach through changing the physiological and biochemical attributes under Cd stress.

Biochar Triggers Systemic Tolerance Against Cobalt Stress in Wheat Leaves Through Regulation of Water Status and Antioxidant Metabolism

“…On the other hand, BC application maintained high levels of chlorophyll fluorescence (F v /F m ) in stress-treated wheat, as compared to stress treatment alone. The elevated F v /F m might be a possible reason for increased chlorophyll content, reduction in ROS levels which induced the degradation of chlorophyll, and enhanced level of N in leaves as correlated with the findings of Akhtar et al (2015), Younis et al (2016), and Amin and Eissa (2017).…”

Hydrogen sulfide alleviates chromium stress on cauliflower by restricting its uptake and enhancing antioxidative system

“…However, the role of H 2 S in regulating Cr tolerance in vegetables such as cauliflower ( Brassica oleracea botrytis L.) is still elusive. Moreover, little information could be found regarding the interactions of H 2 S and Cr contamination in vegetables despite the fact that Cr may accumulate in vegetables and cause contaminations of the food chain (Younis et al ).…”

Impact of Biochar on the Bioremediation and Phytoremediation of Heavy Metal(loid)s in Soil

“…Biochar can reduce toxicity of heavy metal(loid)s and promote the plant growth in heavily contaminated soils [19,56,57], as shown in Figure 1 (process 4). Soils with high available concentrations of toxic metal(loid)s are generally very acidic, unlikely supporting plant germination and growth.…”

“…Soils developed on or around mine tailings are generally very acidic, with high available concentrations of dissolved toxic metal(loid)s, unlikely supporting plant germination and growth. Biochar is very stable with slow-releasing nutrients and readily reduces the plant-available concentrations of cationic metal(loid)s, resulting in the decrease of phytotoxicity of metal(loid)s to plants [19,51,56,57], as the increase of the germination rate [60], root length, and better plant growth [51] are found in the presence of biochar.…”

“…Soil amendments such as biochar facilitate grassland recovery and revegetation in severely degraded habitats, such as mining waste and contaminated soils. For example, biochar reduced the toxicity of heavy metal(loid)s to plant growth in heavily contaminated soils [19,56,57]. Furthermore, biochar can improve soil structure and aeration and provide some necessary nutrients that promote microbial activity and diversity.…”