Tomato plants (Solanum lycopersicum L.) grown in experimental contaminated soil: Bioconcentration of potentially toxic elements and free radical scavenging evaluation.

Concetta Piscitelli,Eleonora Grilli,Margherita Lavorgna,Chiara Russo,Marina Isidori,Rocco De Prisco,Elio Coppola,Branislav T Šiler

doi:10.1371/journal.pone.0237031

Abstract

Tomato is the most widespread vegetable crop in the world. In Italy, tomatoes are mainly cultivated in the South and in the Campania region, precisely in the area called Agro Nocerino-Sarnese. This flatland is affected by an extreme level of environmental degradation, especially related to the Sarno River, where concentrations of Potential Toxic Elements (PTEs) have been found to be higher than the maximum permitted level. The aim of this study was to determine the PTEs uptake by roots and their translocation to the aerial parts of the plants of two cultivars of tomatoes (Pomodoro Giallo and San Marzano Cirio 3). To the purpose, samples of the two cultivars were grown both in pots with experimentally contaminated soil containing: Cr or Cd or Pb at extremely high concentrations and in pots with uncontaminated soils (control). Additionally, the antioxidant properties of the cultivars selected grown on uncontaminated/contaminated soils were assessed. The results showed that Cd was the contaminant that most significantly interfered with the growth of both cultivars of tomato plants, whereas Pb caused lower phenotypical damage. Cd translocation from root to the organs of tomato plants was observed in both cultivars. Specifically, the total amount of Cd found in stems and leaves was higher in the Pomodoro Giallo (254.4 mg/kg dry weight) than in the San Marzano Cirio 3 (165.8 mg/kg dry weight). Cd was the only PTE found in the fruits of both cultivars, with values of 6.1 and 3.9 mg/kg dry weight of Pomodoro Giallo and San Marzano Cirio 3, respectively. The fruits of tomato plants grown in PTEs-contaminated soil showed inhibition or stimulations of the radical scavenging activity compared to the fruits grown in uncontaminated soil. This study highlighted that, despite the relatively high experimental concentrations of PTEs, their translocation to the edible part was comparatively low or absent.

Highlights

The cultivated tomato, Solanum lycopersicum L. endemic to Central and South America, belongs to the family Solanaceae
Despite Cd translocation, phenotypical effects were not observed up to a contamination level of 10% of cation exchange capacity (CEC) while significant differences in the antiradical properties were found for each Potential Toxic Elements (PTEs) and for each cultivar
Concentrations and activities of PTEs modulated antiradical mechanisms with stimulatory or inhibitory responses, which most likely depended on the content of secondary metabolites produced by tomato plants in an effort of self-protection against the exposure to such elements

Summary

Introduction

The cultivated tomato, Solanum lycopersicum L. endemic to Central and South America, belongs to the family Solanaceae It is the world’s most highly grown vegetable due to its status as a basic ingredient in a large variety of raw, cooked or processed foods. Piscitelli et al [6] focused on San Marzano Cirio 3 and Pomodoro Giallo cultivars while studying the antioxidant and antitumoral properties of nine different cultivars of tomatoes. The authors selected those cultivars for their radical scavenging activity (high polyphenolic content) and their antitumoral properties (content of lycopene and carotene). In Italy, tomatoes are mainly cultivated in the South especially in Agro Nocerino Sarnese (Campania Region) since it is one of the most fertile Italian flatlands for tomato production (31x106 kg of tomatoes in open fields and 44x106 kg tomatoes production and processing in open fields) [7]

Objectives

Methods

Results

Conclusion