Cadmium effect on oxidative metabolism of pea (Pisum sativum L.) roots. Imaging of reactive oxygen species and nitric oxide accumulation in vivo

• Published in: Plant, cell and environment Vol. 29; no. 8; pp. 1532 - 1544
• Main Authors: RODRÍGUEZ‐SERRANO, MARÍA, ROMERO‐PUERTAS, MARÍA C., ZABALZA, ANA, CORPAS, FRANCISCO J., GÓMEZ, MANUEL, DEL RÍO, LUIS A., SANDALIO, LUISA M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.2006; Blackwell
• Subjects: antioxidants; Antioxidants - metabolism; Biological and medical sciences; cadmium; Cadmium - pharmacology; Cyclopentanes - metabolism; ethylene; Ethylenes - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant - drug effects; hydrogen peroxide; Hydrogen Peroxide - metabolism; imaging; jasmonic acid; Metabolism; Microscopy, Confocal; Molecular Sequence Data; Nitric Oxide - analysis; Nitric Oxide - metabolism; Oxidation-Reduction - drug effects; Oxidative Stress; Oxygen - metabolism; Oxylipins; Photosynthesis, respiration. Anabolism, catabolism; Pisum sativum; Pisum sativum - anatomy & histology; Pisum sativum - drug effects; Pisum sativum - metabolism; Plant physiology and development; Plant Roots - anatomy & histology; Plant Roots - drug effects; Plant Roots - physiology; Reactive Oxygen Species - analysis; Reactive Oxygen Species - metabolism; salicylic acid; Salicylic Acid - metabolism; Signal Transduction; superoxide; Oxidative stress; NO; Senescence; Xylem; Growth; antioxidants; Ethylene; Superoxide dismutase; NADPH peroxidase; NAD(P)H oxidase; Catalase; Dicotyledones; Angiospermae; Peroxidase; jasmonic acid; Salicylic acid; Root; Enzyme; hydrogen peroxide; Antioxidant; Metabolism; imaging; Leguminosae; Peroxidases; Nitric oxide; Pisum sativum; cadmium; Spermatophyta; Oxidoreductases; superoxide; Reductase
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.1365-3040.2006.01531.x

ABSTRACT Growth of pea (Pisum sativum L.) plants with 50 µm CdCl2 for 15 d produced a reduction in the number and length of lateral roots, and changes in structure of the principal roots affecting the xylem vessels. Cadmium induced a reduction in glutathione (GSH) and ascorbate (ASC) contents, and catalase (CAT), GSH reductase (GR) and guaiacol peroxidase (GPX) activities. CuZn‐superoxide dismutase (SOD) activity was also diminished by the Cd treatment, although Mn‐SOD was slightly increased. CAT and CuZn‐SOD were down‐regulated at transcriptional level, while Mn‐SOD, Fe‐SOD and GR were up‐regulated. Analysis of reactive oxygen species (ROS) and nitric oxide (NO) levels by fluorescence and confocal laser microscopy (CLM) showed an over‐accumulation of O2.− and H2O2, and a reduction in the NO content in lateral and principal roots. ROS overproduction was dependent on changes in intracellular Ca+2 content, and peroxidases and NADPH oxidases were involved. Cadmium also produced an increase in salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) contents. The rise of ET and ROS, and the NO decrease are in accordance with senescence processes induced by Cd, and the increase of JA and SA could regulate the cellular response to cope with damages imposed by cadmium.