Metal contamination in urban street sediment in Pisa (Italy) can affect the production of antioxidant metabolites in Taraxacum officinale Weber

Abstract

Taraxacum officinale Weber (dandelion) is a very ubiquitous species, and it can grow in urban environments on metal-polluted sediments deposited in the gutters. This study represents a preliminary step to verify the presence of metals in sediments collected in urban streets in Pisa and to assess the alteration in dandelion metabolites in order to understand its adaptation to polluted environments. The soil and sediments were collected at three urban streets and analyzed for total and extractable Cr, Pb, Cu, Ni, and Zn. The total values of Pb and Zn in street sediments exceeded the limits for residential areas of soils. Zn was the most mobile of the metals analyzed. Floating cultivations trials were set up with dandelion seedlings and street sediments. The metals were analyzed in roots and leaves. Antioxidant power, anthocyanins, polyphenols, non-protein thiols (NP-TH) and chlorophylls were measured in dandelion leaves. The first two parameters (anthocyanins and antioxidant power) were higher in the polluted samples compared to the control; chlorophyll content was lower in the treated samples, whereas NP-TH showed no differences. NP-TH groups determined in roots were associated with the root content of Zn and Pb. These results indicate that dandelion can tolerate plant stress by altering its metabolite content.

Robinia pseudoacacia and Melandrium album in trace elements biomonitoring and air pollution tolerance index study

“…In the case of high traffic sites such as C2 the content of Zn, Cd, Pb was higher than in the study by Hu et al (2014) at, respectively: 5.26-11.27; 0.48-2.75; 2.15-15.9 mg kg -1 . The soil contamination with Zn and Pb in Pisa (Italy) (Bretzel et al 2014) was at a comparable level to the soil collected in C2 (high traffic). The bioavailability of the investigated metals was low (Table 3).…”

“…Moreover, a positive correlation was found between GSHt and Cd, Zn in the leaves of R. pseudoacacia and Pb, Cd, Zn in M. album. In the leaves of dandelions grown on sediments from the main roads of the inner city of Pisa, the non-protein thiols were lower or were at a comparable level (Bretzel et al 2014). In a previous study in the plants P. lanceolata and C. arenosa from metalliferous sites in the vicinity of smelters and areas connected with former mining activities, lower or comparable level of NP-SH was detected in comparison with plants from the control area (Nadgórska-Socha et al 2013).…”

Salinity-Induced Changes of Photosynthetic Performance, Lawsone, VOCs, and Antioxidant Metabolism in Lawsonia inermis L.

“…The extract was also tested with ferric ion reducing antioxidant power (FRAP) antioxidant assay to confirm the antioxidant activity [ 45 ]. Anthocyanins were extracted from 0.1 g of fresh leaves in ethanol/HCl (99/1, v/v ) and used to read the absorbance at 535 nm [ 46 ]. The total anthocyanin content was expressed as milligrams of malvin chloride equivalents (ME) per gram of fresh weight.…”

Combined effect of silicon and non-thermal plasma treatments on yield, mineral content, and nutraceutical proprieties of edible flowers of Begonia cucullata

“…Two technical replicates of frozen flower samples (200 mg FW) were homogenized in a mortar with 2 ml of cold 70% MeOH and centrifuged at 14,000 rpm for 10 min at 20 • C. The supernatant was used for the quantification of total polyphenols, following the procedure reported by Bretzel et al (2014), as well as the quantification of antioxidant activity. Briefly, the total polyphenols were quantified following the Folin-Ciocalteau procedure using a Gallic acid calibration curve, while the antioxidant activity was determined using the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay that is based on a colorimetric reaction comparing the absorbance at 517 nm against a calibration curve with Trolox (Merck KGaA, Darmstadt, Germany).…”