Oxidative stress and fluctuations of free and conjugated polyamines in the halophyte Mesembryanthemum crystallinum L. under NaCl salinity
The accumulation of conjugated and free polyamines in plants is very important for their protection against oxidative stress induced by abiotic factors. In the present study, the species halophytic plant Mesembryanthemum crystallinum L. was used as a model system in which the process of Crassulacean Acid Metabolism induction is linked with oxidative stress, especially under salinity conditions. A comparative analysis of the content of free polyamines, perchloric (PCA)-soluble and PCA-insoluble conjugated polyamines in mature leaves and roots was carried out with plants exposed to salinity. It was found that adult leaves and roots under normal conditions or salinity (400 mM NaCl) contained all types of free polyamines (putrescine, spermidine, spermine, and cadaverine). In leaves only PCA-insoluble conjugates were found, which showed a tendency to grow with increased duration of salt action (1.5–48 h). In contrast to leaves, in roots all forms of polyamine conjugates (PCA-soluble and -insoluble) were detected. However, the formation of all conjugates, especially PCA-soluble forms in roots, was sharply inhibited by salt shock (400 mM NaCl, 1.5 h) or exogenous cadaverine (1 mM) treatment. PCA-soluble conjugates of cadaverine in roots were found only when the treatment was carried out in combination with aminoguanidine (1 mM), as a result of diamine oxidase inhibition and consequently a decreasing of H2O2 production in plant cells. The activation of diamine oxidase and guaiacol peroxidase by NaCl or exogenous cadaverine was observed in leaves and roots. Thus, the activation of oxidative degradation of polyamines combined with H2O2–peroxidase reaction in cells are involved in the regulation of free and conjugated polyamines titers under salinity.
KeywordsFree and conjugated polyamines Salt and oxidative stresses Mesembryanthemum crystallinum L.
Crassulacean acid metabolism
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The authors are grateful to Professor Nella L. Klyachko from the Institute of Plant Physiology (Moscow, Russia) for valuable assistance in translating this manuscript from Russian into English. This work was partially supported by the Russian Foundation for Basic Research (project no. 04-04-48392) and by the program of the Presidium of RAS (Cell and Molecular Biology).
- Bagni N, Pistocchi R (1991) Uptake and transport of polyamines and inhibitors of polyamine metabolism in plants. In: Slocum RD, Flores HE (eds) Biochemistry and physiology of polyamines in plants. CRC Press, Boca Raton, pp 105–118Google Scholar
- Chance B (1954) Special methods: catalase. In: Glick D (ed) Methods of biochemical analysis. Interscience Publishers, New York, p 408Google Scholar
- Langerbartels C, Kerner K, Leonardi S, Schraudner M, Trost M, Heller W, Sanderman H (1991) Biochemical plant responses to ozone. 1. Differential induction of polyamine and ethylene biosynthesis in tobacco. Plant Physiol 95:882–887Google Scholar
- Ślesak I, Karpińska B, Surówka E, Miszalski Z, Karpiński S (2003) Redox changes on chloroplast and hydrogen peroxide are essential for regulation of C3–CAM transition and photooxidative stress responses in the facultative CAM plant Mesembryanthemum crystallinum L. Plant Cell Physiol 44:573–581PubMedCrossRefGoogle Scholar
- Takahama U (1989) A role of hydrogen peroxyde in the metabolism of phenolics in mesophyll cells of Vicia faba L. Plant Cell Physiol 30:295–301Google Scholar