Exogenous Caffeine (1,3,7-Trimethylxanthine) Application Diminishes Cadmium Toxicity by Modulating Physio-Biochemical Attributes and Improving the Growth of Spinach (Spinacia oleracea L.)

Abstract

Leafy vegetables usually absorb and retain heavy metals more readily than most of the other crop plants, and thus contribute ≥70% of the total cadmium (Cd) intake of humans. Caffeine mediates plant growth and has proved to be beneficial against pathogens and insects. Therefore, it was hypothesized that foliar applications of caffeine could alter metabolism and reduce Cd toxicity in spinach (Spinacia oleracea L.). Seven-day old spinach seedlings were provided with Cd (0, 50, and 100 µM) stress. Caffeine (0, 5, or 10 mM) foliar spray was given twice at after 20 days of seeds germination with an interval of one week. In results, Cd stress reduced photosynthetic pigments biosynthesis, increased oxidative stress, imbalanced nutrient retention, and inhibited plant growth. On the other hand, the caffeine-treated spinach plants showed better growth owing to the enhanced biosynthesis of chlorophylls, better oxidative defense systems, and lower accumulation and transport of Cd within the plant tissues. Furthermore, caffeine application enhanced the accumulation of the proline and ascorbic acid, but reduced MDA and H2O2 contents and Cd in plant leaves, and ultimately improved mineral nutrition of spinach plants exposed to different Cd regimes. In conclusion, exogenous application of caffeine significantly diminishes Cd stress by modulating physiological, biochemical, and growth attributes of spinach (Spinacia oleracea L.)

Appraisal of Heavy Metals Accumulation, Physiological Response, and Human Health Risks of Five Crop Species Grown at Various Distances from Traffic Highway

“…The current study shows that these contents significantly decreased with increasing metal (Pb and Cd) concentrations in plant tissues as shown in Table 4. The chlorophyll and carotenoid contents in plants exhibited the same trend of under Pb and Cd exposure as demonstrated by Emanuil et al [74] and Rahman et al [75]. We observed a decrease in carotenoid contents when the Pb and Cd concentrations were higher.…”

“…Vijayarengan [43] found that increased zinc level in the soil results in decreasing the chlorophyll and carotenoid contents in the leaves of radish plant. A similar change in chlorophyll contents was recorded with Pb and Cd treatments [74,75]. The carotenoid contents decreased with increasing Pb, Cd concentrations demonstrated in various treatments.…”

“…The dry biomass decreased with a decrease in distance from the highway and the minimum value was found at 0-10 m from the highway (Figure 4A-E). Earlier it has been found that the biomass of the plants decreased under the increasing concentration of heavy metals [74,75]. This premise is supported by the concentration of Pb and Cd in different plant species which were increasing with decreasing distance from the road (Tables 2 and 3).…”

Straw Incorporation in Contaminated Soil Enhances Drought Tolerance but Simultaneously Increases the Accumulation of Heavy Metals in Rice

“…Human exposure to HMs has intensely increased due to exponential growth in various industries [6][7][8][9][10]. The solid waste or liquid effluent contaminates water and surface soil, entering the food chain through plants or aquatic organisms and resulting in adverse effects on human health [11].…”

Processing overwhelms biostimulant‐induced vitamin E improvement in lentils

“…During the degradation of caffeine, several metabolites are generated, which could act as modulators of the plant stress response, potentially increasing antioxidant contents and conferring tolerance (Ashihara et al, 2008; Watanabe et al, 2014). Emanuil et al (2022) observed improved plant tolerance and increased antioxidant content in spinach after caffeine application, suggesting the potential use of this alkaloid as a component of biostimulants, which could potentially enhance plant productivity and/or quality.…”