Early and long-term responses of cucumber cells to high cadmium concentration are modulated by nitric oxide and reactive oxygen species
Plants are increasingly exposed to heavy metal pollution in the environment. Cadmium (Cd), a non-essential metal, is known to exert strong phytotoxic effects. The aim of the present study was to examine the role of nitric oxide (NO), reactive nitrogen (RNS) and reactive oxygen (ROS) species in the responses of cucumber (Cucumis sativus) cell culture to high Cd concentration. We observed that the early responses to Cd included enhanced levels of NO, RNS and ROS and the induction of cell death, whereas the levels of both RNS and ROS were suppressed as a long-term response to Cd. The Cd-induced increase of NO level was localized in the chloroplasts, while increased ROS and RNS levels were observed in the cytoplasm. We employed an NO scavenger, an NO synthase inhibitor and an NO donor to evaluate the involvement of RNS and ROS in the responses of C. sativus cells to Cd. The observed changes in cell viability and growth were not related to changes in NO, RNS and ROS levels. Long-term Cd exposure inhibited cell division and de-differentiation as assessed by microcallus formation. We conclude that increased NO level belongs to the early responses of plant cells to high Cd concentration and is associated with an NO synthase-like enzyme activity, whereas decreased cell viability and division in long-term Cd treatment are related to interferences with NO signalling and decreased level of both RNS and ROS.
KeywordsCucumis sativus Protoplasts Cadmium Reactive nitrogen species Reactive oxygen species Microcallus
This research was supported by the Czech Ministry of Education, Youth and Sports (LH11013).
- Barroso JB, Corpas FJ, Carreras A, Rodriguez-Serrano M, Esteban FJ, Fernandez-Ocana A, Chaki M, Romero-Puertas MC, Valderrama R, Sandalio LM, Del Rio LA (2006) Localization of S-nitrosoglutathione and expression of S-nitrosoglutathione reductase in pea plants under cadmium stress. J Exp Bot 57:1785–1793CrossRefPubMedGoogle Scholar
- Bartha B, Kolbert Z, Erdei L (2005) Nitric oxide production induced by heavy metals in Brassica juncea L. Czern. and Pisum sativum L. Acta Biol Szeged 49:9–12Google Scholar
- Besson-Bard A, Gravot A, Richaud P, Auroy P, Duc C, Gaymard F, Taconnat L, Renou JP, Pugin A, Wendehenne D (2009) Nitric oxide contributes to cadmium toxicity in Arabidopsis by promoting cadmium accumulation in roots and by up-regulating genes related to iron uptake. Plant Physiol 149:1302–1315CrossRefPubMedCentralPubMedGoogle Scholar
- Chen F, Wang F, Sun H, Cai Y, Mao W, Zhang G, Vincze E, Wu F (2010) Genotype-dependent effect of exogenous nitric oxide on Cd-induced changes in antioxidative metabolism, ultrastructure, and photosynthetic performance in barley seedlings (Hordeum vulgare). J Plant Growth Regul 29:394–408CrossRefGoogle Scholar
- Gajdová J, Navrátilová B, Smolná J, Lebeda A (2007) Factors affecting protoplast isolation and cultivation of Cucumis spp. J App Bot Food Qual 81:1–6Google Scholar
- Illéš P, Schlicht M, Pavlovkin J, Lichtscheidl I, Baluška F, Ovečka M (2006) Aluminium toxicity in plants: internalization of aluminium into cells of the transition zone in Arabidopsis root apices related to changes in plasma membrane potential, endosomal behaviour, and nitric oxide production. J Exp Bot 57:4201–4213CrossRefPubMedGoogle Scholar
- Ötvös K, Pasternak TP, Miskolczi P, Domoki M, Dorjgotov D, Szucs A, Bottka S, Dudits D, Feher A (2005) Nitric oxide is required for, and promotes auxin-mediated activation of, cell division and embryogenic cell formation but does not influence cell cycle progression in alfalfa cell cultures. Plant J 43:849–860CrossRefPubMedGoogle Scholar
- Rodríguez-Serrano M, Romero-Puertas MC, Zabalza A, Corpas FJ, Gómez M, Del Río LA, Sandalio LM (2006) Cadmium effect on oxidative metabolism of pea (Pisum sativum L.) roots. Imaging of reactive oxygen species and nitric oxide accumulation in vivo. Plant Cell Environ 29:1532–1544CrossRefPubMedGoogle Scholar
- Rodríguez-Serrano M, Romero-Puertas MC, Pazmino DM, Testillano PS, Risueno MC, Del Río LA, Sandalio LM (2009a) Cellular response of pea plants to cadmium toxicity: cross talk between reactive oxygen species, nitric oxide, and calcium. Plant Physiol 150:229–243CrossRefPubMedCentralPubMedGoogle Scholar
- Sandalio LM, Dalurzo HC, Gomez M, Romero-Puertas MC, Del Rio LA (2011) Cadmium–induced changes in the growth and antioxidative metabolism of pea plants. J Exp Bot 52:2115–2126Google Scholar