Estimating tomato tolerance to heavy metal toxicity: cadmium as study case

Author(s)

Piotto, Fernando Angelo ; Amaral Carvalho, Marcia Eugenia ; Souza, Lucas Anjos ; Silva Rabelo, Flavio Henrique ; Franco, Monica Regina ; Batagin-Piotto, Katherine Derlene ; Azevedo, Ricardo Antunes

• Document type: Journal article
• Source: Environmental Science and Pollution Research; v. 25, n. 27, p. 10-pg., 2018-09-01.

Abstract

This work aimed to develop a reliable and fast approach to estimate the plant tolerance degree to heavy metal (HM) phytotoxicity. Two independent experiments were carried out using tomato accessions, with contrasting morphological features, that were grown in a hydroponic solution containing different CdCl2 concentrations for 7 days. Plant dry weight and chlorophyll content (SPAD units) were evaluated, and tolerance degree to Cd toxicity was estimated according to the tolerance index (TI), which is a new mathematical formula based on plant biomass proposed in this study. Although with different magnitudes, tomato exhibited reductions in their dry weight concurrently with the increasing CdCl2 concentration. By contrast, chlorophyll content presented no standard response, decreasing and even increasing according to CdCl2 concentrations, indicating that only under certain conditions (particularly, at CdCl2 50 mu M), this parameter can be used to estimate plant tolerance to Cd toxicity. TI was efficiently able to segregate tomato cultivars with similar performance (based on the total dry weight of plants), and such segregation was optimized when the hydroponic solution contained from 25 to 50 mu M CdCl2. Within this range, data pointed at 35 mu M CdCl2 as the best concentration to be employed in studies related to the tomato tolerance/sensitivity to Cd toxicity. In conclusion, TI proved to be a reliable estimator of tolerance degree to Cd exposure in genetically distinct tomato accessions. Moreover, TI can be used for this same purpose in plants under other HM-induced stresses. (AU)

• FAPESP's process: 13/15217-5 - INTEGRATED APPROACH OF ANATOMICAL, PHYSIOLOGICAL, BIOCHEMICAL AND MOLECULAR PARAMETERS FOR THE STUDY OF TOLERANCE MECHANISMS TO CADMIUM IN TOMATO ACCESSION
• Grantee: Marcia Eugenia Amaral de Carvalho
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/54676-0 - Oxidative stress induced by metals: new approaches
• Grantee: Ricardo Antunes de Azevedo
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/26640-1 - Study of tolerance mechanisms to cadmium in tomato accessions: molecular approaches
• Grantee: Marcia Eugenia Amaral de Carvalho
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 16/05788-3 - Characterization of Cd tolerance mechanisms in tomato roots using tolerant rootstocks
• Grantee: Katherine Derlene Batagin Piotto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 12/03861-4 - Determination of parameters to cadmium tolerance in tomato plants (Solanum Lycopersicum L.)
• Grantee: Fernando Angelo Piotto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral