Lettuce irrigated with contaminated water: Photosynthetic effects, antioxidative response and bioaccumulation of microcystin congeners

Author(s)

Bittencourt-Oliveira, Maria do Carmo ^{[1, 2]} ; Cordeiro-Araujo, Micheline Kezia ^{[1, 2]} ; Chia, Mathias Ahii ^[1] ; de Toledo Arruda-Neto, Joao Dias ^{[3, 4]} ; de Oliveira, Enio Tiago ^[1] ; dos Santos, Flavio ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Ciencias Biol, Escola Super Agr Luiz de Queiroz, Ave Padua Dias 11, BR-13418900 Sao Dimas Piracicaba, SP - Brazil

^[2] Univ Fed Rural Pernambuco, Programa Posgrad Bot, R Dom Manoel de Medeiros S-N, BR-52171030 Recife, PE - Brazil

^[3] Univ Sao Paulo, Inst Fis, Rua Matao Travessa R Nr 187, BR-05508090 Cidade Univ, SP - Brazil

^[4] FESP Sao Paulo Engn Coll, Ave 9 Julho, 5520 Jardim Europa, BR-01406200 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 128, p. 83-90, JUN 2016.
• Web of Science Citations: 24

Abstract

The use of microcystins (MCs) contaminated water to irrigate crop plants represents a human health risk due to their bioaccumulation potential. In addition, MCs cause oxidative stress and negatively influence photosynthetic activities in plants. The present study was aimed at investigating the effect of MCs on photosynthetic parameters and antioxidative response of lettuce. Furthermore, the bioaccumulation factor (BAF) of total MCs, MC-LR and MC-RR in the vegetable after irrigation with contaminated water was determined. Lettuce crops were irrigated for 15 days with water containing cyanobacterial crude extracts (Microcystis aeruginosa) with MC-LR (0.0, 0.5, 2.0, 5.0 and 10.0 mu g L-1), MC-RR (0.0, 0.15, 0.5, 1.5 and 3.0 mu g L-1) and total MCs (0.0, 0.65, 2.5, 6.5 and 13.0 mu g L-1). Increased net photosynthetic rate, stomatal conductance, leaf tissue transpiration and intercellular CO2 concentration were recorded in lettuce exposed to different MCs concentrations. Antioxidant response showed that glutathione S-transferase activity was down-regulated in the presence of MCs. On the other hand, superoxide dismutase, catalase and peroxidase activities were upregulated with increasing MCs concentrations. The bioaccumulation factor (BAF) of total MCs and MC-LR was highest at 6.50 and 5.00 mu g L-1, respectively, while for MC-RR, the highest BAF was recorded at 1.50 mu g L-1 concentration. The amount of total MCs, MC-LR and MC-RR bioacumulated in lettuce was highest at the highest exposure concentrations. However, at the lowest exposure concentration, there were no detectable levels of MC-LR, MC-RR and total MCs in lettuce. Thus, the bioaccumulation of MCs in lettuce varies according to the exposure concentration. In addition, the extent of physiological response of lettuce to the toxins relies on exposure concentrations. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 13/11306-3 - The Effects of anatoxin-a and cylindrospermopsin at different nitrogen concentrations and photon irradiances on the physiology of Microcystis aeruginosa (Cyanobacteria) and Scenedesmus acuminatus (Chlolrophyta)
• Grantee: Mathias Ahii Chia
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/01934-0 - Bioaccumulation and detoxification study of cyanobacteria toxins (microcystins and cilindrospermopsin) in lettuce and arugula
• Grantee: Maria Do Carmo Bittencourt de Oliveira
• Support Opportunities: Regular Research Grants