Abstracts
Abstract
Exposure of Azolla plants to UV-B radiation for 6 h resulted in a decrease in biomass and relative growth rate (RGR), which coincided with an increase in doubling time (DT) as compared with the control. Also, the protein content decreased. On the other hand, hydrogen peroxyde (H2O2) and malondialdehyde (MDA) accumulated significantly in UV-treated Azolla plants. Conversely, the addition of selenium (Se) at 1 ppm resulted in a significant increase in biomass and protein content of untreated and UV-treated Azolla plants, and a significant reduction in both H2O2 and MDA. Moreover, the addition of Se to UV-treated and untreated Azolla plants resulted in a significant increase in total ascorbate and total glutathione (GSH) contents compared with the control and UV-stressed Azolla plants. Also, glutathione redox potential (GSH/TG) increased significantly in UV-treated Azolla plants in the presence of Se. There also was a significant increase (38%) in ascorbate peroxidase (APX) activity in UV-treated plants compared with the control. APX activity in the presence of Se did not change significantly compared with the control. Glutathione reductase (GR) activity increased significantly in UV-treated Azolla, while glutathione peroxidase (GSH-PX) activity did not. On the other hand, both GSH-PX and GR activity in untreated and UV-treated Azolla plants were significantly enhanced by the application of Se to the nutrient media at a concentration of 1 ppm. Therefore, we can conclude that Se protects Azolla plants from UV-B stress.
Keywords:
- ascorbate,
- Azolla caroliniana,
- glutathione,
- glutathione peroxidase,
- selenium,
- UV-B radiation
Résumé
L’exposition de plants d’Azolla au rayonnement UV-B pendant 6 h a provoqué une diminution de la biomasse et du taux de croissance relative (TCR), coïncidant avec une augmentation du temps de doublement (TD) comparativement au témoin. Aussi, le contenu en protéines a diminué. Par contre, le peroxyde d’oxygène (H2O2) et le malondialdéhyde (MDA) se sont accumulés de façon significative dans les plants d’Azolla traités par rayonnement UV. À l’inverse, l’ajout de 1 ppm de sélénium (Se) a provoqué une augmentation importante de la biomasse et du contenu en protéines des plants d’Azolla exposés ou non au rayonnement UV, ainsi qu’une réduction importante du H2O2 et du MDA. De plus, l’ajout de Se a provoqué une augmentation importante du contenu total d’ascorbate et de glutathion chez les plants d’Azolla exposés ou non au rayonnement UV comparativement au témoin et aux plants d’Azolla exposés au rayonnement UV en présence de Se. Aussi, le potentiel d’oxydoréduction de glutathion (NrH) a augmenté significativement chez les plants d’Azolla exposés au rayonnement UV en présence de Se. Il y a également eu une augmentation importante (38 %) de l’activité d’ascorbate peroxydase (APX) chez les plants exposés au rayonnement UV comparativement au témoin. L’activité APX en présence de Se n’a pas changé de façon significative comparativement au témoin. L’activité de glutathion réductase (GR) a augmenté significativement chez l’Azolla exposé au rayonnement UV, mais ce n’était pas le cas pour l’activité de glutathion peroxydase (GSH-PX). Toutefois, l’activité de GSH-PX et l’activité de GR dans les plants d’Azolla traités ou non par rayonnement UV ont été rehaussées de façon significative par l’application de Se aux milieux nutritifs à une concentration de 1 ppm. Ainsi, nous pouvons conclure que le Se protège les plants d’Azolla du stress relié au rayonnement UV-B.
Mots-clés :
- ascorbate,
- Azolla caroliniana,
- glutathion,
- glutathion peroxydase,
- rayonnement UV-B,
- sélénium
Appendices
Bibliography
- Agrawal, S.B. 1992. Effect of supplemental UV-B radiation on photosynthetic pigment, protein and glutathione contents in green algae. Environ. Exp. Bot. 32 : 137-143.
- Asada, K. 1994. Production and action of active oxygen species in photosynthetic tissues. Pages 77-104 in C.H. Foyer and P.M. Mullineaux (eds.) Causes of Photooxidative Stress and Amelioration of Defense Systems in Plants. CRC Press, Boca Raton, FL, USA.
- Bradford, M.M. 1976. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72 : 248–254.
- Cartes, P., L. Gianfreda and M.L. Mora. 2005. Uptake of selenium and its antioxidant activity in ryegrass when applied as selenate and selenite forms. Plant Soil 276 : 359-367.
- Costa, H., S.M. Gallego and M.L. Tomaro. 2002. Effect of UV-B radiation on antioxidant defense system in sunflower cotyledons. Plant Sci. 162 : 939-945.
- Dai, Q., B. Yan, S. Huang, X. Liu, S. Peng, M. Lourdes, L. Miranda, A.Q. Chavez, B.S. Vergara and D.M. Olszyk. 1997. Response of oxidative stress defense systems in rice (Oryza sativa) leaves with supplemental UV-B radiation. Physiol. Plant. 101 : 301-308.
- Djanaguiraman, M., D.D. Devi, A.K Shanker, J.A. Sheeba and U. Bangarusamy. 2005. Selenium – an antioxidative protectant in soybean during senescence. Plant Soil 272 : 77–86.
- El-Aggan, W. 1982. A comparative study of the growth and nitrogenase activity of five Azolla species as affected by various environmental factors. Ph.D. Thesis, Université catholique de Louvain, Louvain, Belgium.
- Feng, R.W. and C.Y. Wei. 2012. Antioxidative mechanisms on selenium accumulation in Pteris vittata L., a potential selenium phytoremediation plant. Plant Soil Environ. 58 : 105–110.
- Feng, R.W., W. Chaoyang and T. Shuxin. 2013. The roles of selenium in protecting plants against abiotic stresses. Environ. Exp. Bot. 87 : 58–68.
- Feng, R.W., C.Y. Wei, S.X. Tu, S.R. Tang and F.C. Wu. 2011. Detoxification of antimony by selenium and their interaction in paddy rice under hydroponic conditions. Microchem. J. 97 : 57–61.
- Flohé, L. and W.A. Günzler. 1984. Assays of glutathione per-oxidase. Meth. Enzymol. 105 : 114–121.
- Gossett, D.R., E.P. Millhollon and M.C. Lucas. 1994. Antioxidant response to NaCl stress in salt-tolerant and salt-sensitive cultivars of cotton. Crop Sci. 34 : 706–714.
- Griffith, O.W. 1980. Determination of glutathione and glutathione disulphide using glutathione reductase and 2-vinyl/pyridine. Anal. Biochem. 106 : 207–212.
- Halliwell, B. and C.H. Foyer. 1978. Properties and physiological function of a glutathione reductase purified from spinach leaves by affinity chromatography. Planta 139 : 9–17.
- Hartikainen, H. and T. Xue. 1999. The promotive effect of selenium on plant growth as triggered by ultraviolet irradiation. J. Environ. Qual. 28 : 1372–1375.
- Hartikainen, H., T. Xue and V. Piironen. 2000. Selenium as an anti-oxidant and pro-oxidant in ryegrass. Plant Soil 225 : 193–200.
- Hasanuzzaman, M. and M. Fujita. 2011. Selenium pretreatment upregulates the antioxidant defense and methyl-glyoxal detoxification system and confers enhanced tolerance to drought stress in rapeseed seedlings. Biol. Trace Elem. Res. 143 : 1758–1776.
- Hassan, A.M.A. and E.M. Mostafa. 2015. Selenium invoked antioxidant defense system in Azolla caroliniana plant. Phyton (accepted).
- Ibrahim, M.M. and E.M. Mostafa. 2007. UV-B effect on constituents of Azolla caroliniana. Z. Naturforsch. Sect. C J. Biosci. 62 : 246–252.
- Kakani, V.G., K.R. Reddy, D. Zhao and K. Sailaja. 2003. Field crop responses to ultraviolet-B radiation. A review. Agric. For. Meteorol. 120 : 191–218.
- Kápolna, E., P.R. Hillestrøm, K.H. Laursen, S. Husted and E.H. Larsen. 2009. Effect of foliar application of selenium on its uptake and speciation in carrot. Food Chem. 115 : 1357–1363.
- Kong, L., M. Wang and D. Bi. 2005. Selenium modulates the activities of antioxidant enzymes, osmotic homeostasis and promotes the growth of sorrel seedlings under salt stress. Plant Growth Regul. 45 : 155−163.
- Kumar, M., A.J. Bijo, R.S. Baghel, C.R.K. Reddy and B. Jha. 2012. Selenium and spermine alleviates cadmium induced toxicity in the red seaweed Gracilaria dura by regulating antioxidants system and DNA methylation. Plant Physiol. Biochem. 51 : 129–138.
- Lesser, M.P., J.J. Cullen and P.J. Neale. 1994. Carbon uptake in a marine diatom during acute exposure to ultraviolet B radiation: relative importance of damage and repair. J. Phycol. 30 : 183–192.
- Lyons, G.H., Y. Genc, K. Soole, J.C.R. Stangoulis, F. Liu and R.D. Graham. 2009. Selenium increases seed production in Brassica. Plant Soil 318 : 73–80.
- Mahdavian, K., M. Ghorbanli and Kh.M. Kalantari. 2008. The effects of ultraviolet radiation on some antioxidant compounds and enzymes in Capsicum annuum L. Turk. J. Bot. 32 : 129–134.
- Malik, J.A., S. Goel, N. Kaur, S. Sharma, I. Singh and H. Nayyar. 2012. Selenium antagonises the toxic effects of arsenic on mungbean (Phaseolus aureus Roxb.) plants by restricting its uptake and enhancing the antioxidative and detoxification mechanisms. Environ. Exp. Bot. 77 : 242–248.
- Mittler, R. 2002. Oxidative stress, antioxidants and stress tolerance. Trends Plant Sci. 7 : 405–410.
- Moron, M.S., J.W. Depierre and B. Mannervik. 1979. Levels of glutathione, glutathione reductase and glutathione S-transferase activities in rat lung and liver. Biochim. Biophys. Acta 582 : 67–78.
- Nakano, Y. and K. Asada. 1981. Hydrogen peroxide is scavenged by ascorbate-specific peroxidase in spinach chloroplasts. Plant Cell Physiol. 22 : 867–880.
- Nasibi, F. and K. M-Kalantari. 2005. The effects of UV-A, UV-B and UV-C on protein and ascorbate content, lipid peroxidation and biosynthesis of screening compound in Brassica napus. Iran. J. Sci. Technol. Trans. A: Sci. 29 : 39–48.
- Oser, B.L. 1979. Hawks Physiological Chemistry. McGraw Hill, New York, NY, USA.
- Parida, A.K., A.B. Das and P. Mohanty. 2004. Defense potentials to NaCl in a mangrove, Bruguiera parviflora: Differential changes of isoforms of some antioxidative enzymes. J. Plant Physiol. 161 : 531–542.
- Pennanen, A., T. Xue and H. Hartikainen. 2002. Protective role of selenium in plant subjected to severe UV irradiation stress. J. Appl. Bot. 76 : 66-76.
- Peters, G.A., B.C. Mayne, T.B. Ray and R.E. Toia. 1979. Physiology and biochemistry of the Azolla-Anabaena symbiosis. Pages 325–344 in Nitrogen and Rice. International Research Institute, Los Baños, Philippines.
- Rayman, M.P. 2002. The argument for increasing selenium intake. Proc. Nutr. Soc. 61 : 203–215.
- Selvakumar, V. 2008. Ultraviolet-B radiation (280-315 nm) invoked antioxidant defence system in Vigna unguiculata (L.) Walp. and Crotalaria juncea L. Photosynthetica 46 : 98–106.
- Seppänen, M., M. Turakainen and H. Hartikainen. 2003. Selenium effects on oxidative stress in potato. Plant Sci. 165 : 311−319.
- Subudhi, B.P.R. and I. Watanabe. 1981. Differential phosphorus requirements of Azolla species and strains in phosphorus-limited continuous culture. Soil Sci. Plant Nutr. 27 : 237–247.
- Takeda, T., T. Ishikawa and S. Shigeoka. 1997. Metabolism of hydrogen peroxide by the scavenging system in Chlamydomonas reinhardtii. Physiol. Plant. 99 : 49–55.
- Terry, N., A.M. Zayed, M.P. de Souza and A.S. Tarun. 2000. Selenium in higher plants. Annu. Rev. Plant Physiol. Plant Mol. Biol. 51 : 401–432.
- Turakainen M., H. Hartikainen and M.M. Seppänen. 2004. Effects of selenium treatments on potato (Solanum tuberosum L.) growth and concentrations of soluble sugars and starch. J. Agric. Food Chem. 52 : 5378–5382.
- Valkama, E., M. Kivimäenpää, H. Hartikainen and A. Wulff. 2003. The combined effects of enhanced UV-B radiation and selenium on the growth, chlorophyll fluorescence and ultrastructure in strawberry (Fragaria x ananassa) and barley (Hordeum vulgare) treated in the field. Agric. For. Meteorol. 120 : 267−278.
- Velikova, V., I. Yordanov and A. Edreva. 2000. Oxidative stress and some antioxidant system in acid rain-treated bean plants: protective role of exogenous polyamines. Plant Sci. 151 : 59-66.
- Wang, S.W., B.T. Xie, L.N. Yin, L.S. Duan, Z.H. Li, A.E. Eneji, W. Tsuji and A. Tsunekawa. 2010. Increased UV-B radiation affects the viability, reactive oxygen species accumulation and antioxidant enzyme activities in Maize (Zea mays L.) pollen. Phytochem. Photobiol. 86 : 110-116.
- Xue, T. and H. Hartikainen. 2000. Association of antioxidative enzymes with the synergistic effect of selenium and UV irradiation in enhancing plant growth. Agric. Food Sci. Finl. 9 : 177–186.
- Xue, T., H. Hartikainen and V. Piironen. 2001. Antioxidative and growth-promoting effect of selenium on senescing lettuce. Plant Soil 237 : 55–61.
- Yao, X.Q., J.Z. Chu and C.J. Ba. 2010. Antioxidant responses of wheat seedlings to exogenous selenium supply under enhanced ultraviolet-B. Biol. Trace Elem. Res. 136 : 96–105.
- Zhang, J. and M.B. Kirkham. 1996. Enzymatic responses of the ascorbate-glutathione cycle to drought in sorghum and sunflower plants. Plant Sci. 113 : 139–147.
- Zhang, L., A.R. Ackley and E.A.H. Pilon-Smits. 2007. Variation in selenium tolerance and accumulation among 19 Arabidopsis thaliana accessions. J. Plant Physiol. 164 : 327-336.