The crucial role of roots in increased cadmium-tolerance and Cd-accumulation in the pea mutant SGECdt
- 100 Downloads
Elucidation of mechanisms underlying plant tolerance to cadmium, a widespread toxic soil pollutant, and accumulation of Cd in plants are urgent tasks. For this purposes, the pea (Pisum sativum L.) mutant SGECdt (obtained by treatment of the laboratory pea line SGE with ethylmethane sulfonate) was reciprocally grafted with the parental line SGE, and four scion/rootstock combinations were obtained: SGE/SGE, SGECdt/SGECdt, SGE/SGECdt, and SGECdt/SGE. They were grown in hydroponics in the presence of 1 μM CdCl2 for 30 d. The SGE and SGECdt scions on the SGECdt rootstock had a higher root and shoot biomass and an elevated root and shoot Cd content compared with the grafts having SGE rootstock. Only the grafts with the SGE rootstock showed chlorosis and roots demonstrating symptoms of Cd toxicity. The content of nutrient elements in roots (Fe, K, Mg, Mn, Na, P, and Zn) was higher in the grafts having the SGECdt rootstock, and three elements, namely Ca, Fe, and Mn, were efficiently transported by the SGECdt root to the shoot of these grafts. The content of other measured elements (K, Mg, Na, P, and Zn) was similar in the root and shoot in all the grafts. Then, the non-grafted plants were grown in the presence of Cd and subjected to deficit or excess concentrations of Ca, Fe, or Mn. Exclusion of these elements from the nutrient solution retained or increased differences between SGE and SGECdt in growth response to Cd toxicity, whereas excess of Ca, Fe, or Mn decreased or eliminated such differences. The obtained results assign a principal role of roots to realizing the increased Cd-tolerance and Cdaccumulation in the SGECdt mutant. Efficient translocation of Ca, Fe, and Mn from roots to shoots appeared to counteract Cd toxicity, although Cd was actively taken up by roots and accumulated in shoots.
Additional key wordscalcium grafting heavy metals iron magnesium manganese phosphorus potassium sodium zinc
Unable to display preview. Download preview PDF.
- Liu, H., Zhang, Y., Chai, T., Tan, J., Wang, J., Feng, S., Liu, G.: Manganese-mitigation of cadmium toxicity to seedling growth of Phytolacca acinosa Roxb. is controlled by the manganese/cadmium molar ratio under hydroponic conditions. - Plant Physiol. Biochem. 73: 144–153, 2013.CrossRefPubMedGoogle Scholar
- Rodriguez-Hernandez, M.C., Bonifas, I., Alfaro-De la Torre, M.C., Flores-Flores, J.L., Banuelos-Hernandez, B., Patino-Rodriguez, O.: Increased accumulation of cadmium and lead under Ca and Fe deficiency in Typha latifolia: A study of two pore channel (TPC1) gene responses. - Environ. exp. Bot. 115: 38–48, 2015.CrossRefGoogle Scholar
- Rodriguez-Serrano, M., Romero-Puertas, M.C., Pazmino, D.M., Testillano, P.S., Risueno, M.C., Del Rio, L.A., Sandalio, L.M.: Cellular response of pea plants to cadmium toxicity: cross talk between reactive oxygen species, nitric oxide, and calcium. - Plant Physiol. 150: 229–243, 2009.CrossRefPubMedPubMedCentralGoogle Scholar
- Tsyganov, V.E., Zhernakov, A.I., Khodorenko, A.V., Kisutin, P.Y., Belimov, A.A., Safronova, V.I., Naumkina, T.S., Borisov, A.Y., Lindblad, P., Dietz, K.J., Tikhonovich, I.A.: Mutational analysis to study the role of genetic factors in pea adaptation to stresses during development its symbioses with Rhizobium and mycorrhizal fungi. - In: Wang, Y.P., Lin, M., Tian, Z.X., Elmerich, C., Newton, W.E. (ed.): Bacterial Nitrogen Fixation, Sustainable Agriculture and the Environment. Pp. 279–281. Springer, Dordrecht 2005.CrossRefGoogle Scholar
- Watanabe, A., Ito, H., Chiba, M., Ito, A., Shimizu, H., Fuji, S., Nakamura, S., Hattori, H., Chino, M., Satoh-Nagasawa, N., Takahashi, H., Sakurai, K., Akagi, H.: Isolation of novel types of Arabidopsis mutants with altered reactions to cadmium: cadmium-gradient agar plates are an effective screen for the heavy metal-related mutants. - Planta 232: 825–836, 2010.CrossRefPubMedGoogle Scholar