Programmed cell death induced by cadmium stress and/or boron deprivation in tobacco (Nicotiana tabacum L.) cultivar Bright Yellow 2 cells
- 36 Downloads
Cadmium (Cd) is one of the most toxic and widespread heavy metal pollutants in soil. As an essential mineral nutrient, boron (B) plays critical roles in physiological processes of plants. In the present study, programmed cell death (PCD) induced by Cd stress and/or B deprivation was assessed and the underlying mechanisms were clarified in suspension-cultured Nicotiana tabacum L. cultivar Bright Yellow 2 (TBY-2) cells. The PCD in TBY-2 cells was analyzed by Hoechst 33258 staining and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and then, expression analysis of PCD-related genes was performed using quantitative real-time polymerase chain reaction (qPCR) assays. The production of reactive oxygen species (ROS) was determined using fluorescence microscopy of 2′,7′-dichlorofluorescein diacetate–labeled cells. The levels of lipid peroxides were quantified by the thiobarbituric acid–reactive substances (TBARS) method. Cadmium stress and/or B deprivation treatments induced PCD that was characterized by a significant increase in the percentage of cells stained with Hoechst 33258 or TUNEL-positive cells, and upregulation or downregulation of the expression of PCD-related genes. Treatments with Cd stress and/or B deprivation increased ROS production and the level of lipid peroxides compared to those of the control group. These data showed that in TBY-2 cells Cd stress and/or B deprivation activated ROS signaling pathways, leading to gene expression that was connected with the PCD process.
KeywordsBoron deficiency Cadmium stress Programmed cell death Reactive oxygen species Gene expression
The Liaoning Key Laboratory for Ecologically Comprehensive Utilization of Boron Resources and Materials, Northeastern University, Liaoning, Shenyang, China, supported this work.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
- Ikenaka Y, Nakayama SMM, Muzandu K, Choongo K, Teraoka H, Mizuno N, Ishizuka M (2010) Heavy metal contamination of soil and sediment in Zambia. Afr J Environ Sci Technol 4:729–739Google Scholar
- Kenneth JL, Thomas DS (2001). Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method. 25:402–408Google Scholar
- Olmos E, Martinez-Solano JR, Piqueras A, Hellin E (2003) Early steps in the oxidative burst induced by cadmium in cultured tobacco cells (BY-2 line). J Exp Bot 54:291–301Google Scholar
- Rustérucci C, Montillet JL, Agnel JP, Battesti C, Alonso B, Knoll A, Bessoule JJ, Etienne P, Suty L, Blein JP, Triantaphylidès C (1999) Involvement of lipoxygenase-dependent production of fatty acid hydroperoxides in the development of the hypersensitive cell death induced by cryptogein on tobacco leaves. J Bio Chem 274:36446–36455CrossRefGoogle Scholar
- Schützendübel A, Polle A (2002) Plant responses to abiotic stresses: heavy metal-induced oxidative stress and protection by mycorrhization. J Exp Bot 53:1351–1365Google Scholar
- Siedlecka A, Krupa Z (1996) Interaction between cadmium and iron and its effects on photosynthetic capacity of primary leaves of Phaseolus vulgaris. Plant Physiol Bioch 34:833–841Google Scholar
- Vacca RA, de Pinto MC, Valenti D, Passarella S, Marra E, De Gara L (2004) Production of reactive oxygen species, alteration of cytosolic ascorbate peroxidase, and impairment of mitochondrial metabolism are early events in heat shock-induced programmed cell death in tobacco bright-yellow 2 cells. Plant Physiol 134:1100–1112CrossRefGoogle Scholar
- Wang Q (1998) In integrated amendment and ecological restoration of polluted soil by heavy metals. Proceedings for strategy of soil environmental protection in the new century of China. Oct, Beijing, pp 26–28Google Scholar
- Wang Q, Li J (1999) Fertilizer proper use and sustainable development of soil environment in China. Adv Environ Sci 7:116–124Google Scholar