Destabilization of ROS metabolism in tomato roots as a phytotoxic effect of meta-tyrosine.
Plant Physiol Biochem
; 123: 369-377, 2018 Feb.
Article
em En
| MEDLINE
| ID: mdl-29304482
ABSTRACT
meta-Tyrosine (m-Tyr) is a non-protein amino acid produced in both plants and animals. Primary mode of action of this phenylalanine analog is its incorporation into protein structure leading to formation of aberrant molecules. An increased level of m-Tyr in animal cells is detected under oxidative stress and during age-related processes characterized by overproduction of reactive oxygen species (ROS). The aim of this study was to link m-Tyr physiological action to disturbances in ROS metabolism in tomato (Solanum lycopersicum L.) seedlings roots. Treatment of tomato seedlings with m-Tyr (50 or 250⯵M) for 24-72â¯h led to inhibition of root growth without a lethal effect. Toxicity of m-Tyr after 72â¯h was connected with an increase in hydrogen peroxide concentration in roots and ROS leakage into the surrounding medium. On the contrary, membrane permeability and lipid peroxidation in roots were the same as for the control. This was accompanied by a decrease in total antioxidant activity and an increased accumulation of phenolic compounds. Catalase (CAT) activity declined in roots exposed to 50⯵M m-Tyr after 24â¯h while after 72â¯h activity of this enzyme was inhibited in both treated and non-treated samples. Activities of different superoxide dismutase (SOD) isoforms were similar in m-Tyr stressed roots and in the control. Prolonged culture resulted in decrease of transcript level of genes coding CAT and SOD with the exception of FeSOD. Moreover, m-Tyr increased the level of protein carbonyl groups indicating induction of oxidative stress as a non-direct mode of action.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tirosina
/
Espécies Reativas de Oxigênio
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Solanum lycopersicum
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Raízes de Plantas
Idioma:
En
Revista:
Plant Physiol Biochem
Assunto da revista:
BIOQUIMICA
/
BOTANICA
Ano de publicação:
2018
Tipo de documento:
Article