Generation of reactive oxygen species in thylakoids from senescing flag leaves of the barley varieties Lomerit and Carina
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During senescence, production of reactive oxygen species increased in thylakoids. In two barley varieties, no difference in superoxide production was observed while singlet oxygen production increased only in one variety.
During senescence, chlorophyll content decreased and photosynthetic electron transport was inhibited as shown for flag leaves collected from barley varieties Lomerit and Carina grown in the field. Spin trapping electron paramagnetic resonance (EPR) was used to investigate the production of reactive oxygen species in thylakoid membranes during senescence. EPR measurements were performed with specific spin traps to discriminate between singlet oxygen on one hand and reactive oxygen intermediates on the other hand. The results show that the generation of reactive oxygen intermediates increases in both varieties during senescence. Singlet oxygen increased only in the variety cv. Lomerit while it remained constant at a low level in the variety cv. Carina. Measurements in the presence of inhibitors of photosystem II and of the cytochrome b6f complex revealed that in senescing leaves reduction of oxygen at the acceptor side of photosystem I was the major, but not the only source of superoxide anions. This study shows that during senescence the production of individual reactive oxygen species varies in different barley varieties.
KeywordsSpin trapping electron paramagnetic resonance Reactive oxygen species Thylakoids Photosynthetic electron transport Barley
2-Iodo-2′,4′,4′-trinitro-3-methyl-6-isopropyl diphenyl ether
Electron paramagnetic resonance
Light harvesting complex
Reactive oxygen species
We thank Rüdiger Stroeh (farm manager of Hohenschulen, CAU, Kiel, Germany) and his co-workers for preparation of field plots. We also thank the early stage researchers Wera Kucharewicz and Aditi Das of the EU Marie Curie project “Croplife” (ITN: PITN-GA-2010-264394) for collecting samples and Luca Boschian for preparation of chloroplasts in 2013. DEPMPO was a kind gift of S. Pietri, Univeristé Aix-Marseille, France. This work was supported by the German Research Foundation (DFG) for financial support (KR1350/13-1, KR1350/14-1).
- Buchanan-Wollaston V, Page T, Harrison E, Breeze E, Lim PO, Nam HG, Lin JF, Wu SH, Swidzinski J, Ishizaki K, Leaver C (2005) Comparative transcriptome analysis reveals significant differences in gene expression and signalling pathways between developmental and dark/starvation-induced senescence in Arabidopsis. Plant J 42:567–585CrossRefPubMedGoogle Scholar
- Coste S, Baraloto C, Leroy C, Marcon E, Renaud A, Richardson AD, Roggy JC, Schimann H, Uddling J, Hérault B (2010) Assessing foliar chlorophyll contents with the SPAD-502 chlorophyll meter: a calibration test with thirteen tree species of tropical rainforest in French Guiana. Ann For Sci 67:607. doi: 10.1051/forest/2010020 CrossRefGoogle Scholar
- Edge R, Truscott T (2010) Properties of carotenoid radicals and excited states and their potential role in biological systems. In: Landrum J (ed) Carotenoids: physical, chemical, and biological functions and properties. CRC Press, Boca Raton, pp 283–307Google Scholar
- Frejaville C, Karoui H, Tuccio B, Lemoigne F, Culcasi M, Pietri S, Lausicella R, Tordo P (1995) 5-(Diethoxyphosphoryl)-5-methyl-1-pyrroline N-oxide—a neW efficient phosphorylated Nitrone for the in vitro and in vivo spin-trapping of oxygen-centered radicals. J Med Chem 38:258–265CrossRefPubMedGoogle Scholar
- Mulisch M, Krupinska K (2013) Ultrastructural analyses of senescence associated dismantling of chloroplasts revisited. In: Biswal B, Krupinska K, Biswal UC (eds) Plastid development in leaves during growth and senescence. Springer, Dordrecht, pp 529–550Google Scholar
- Porra RJ, Thompson WA, Kriedemann PE (1989) Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: verification of the concentration of chlorophyll standards by atomic absorption spectroscopy. Biochim Biophys Acta 975:384–394CrossRefGoogle Scholar