Physiological and biochemical response of potato (Solanum tuberosum L. cv. Kara) to O3 and antioxidant chemicals: possible roles of antioxidant enzymes |
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Authors: | I.A. Hassan |
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Affiliation: | Department of Botany, Faculty of Science, Alexandria University, El-Shatby, Alexandria, Egypt |
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Abstract: | An Egyptian cultivar of potato (Solanum tuberosum L. cv. Kara) was grown in the field at two locations in northern Egypt: a ‘rural’ and a ‘suburban’ site, from October 2000 and November 2002. The antiozonant ethylenediurea (EDU) and the fungicide chlorothalonil (1,3‐benzenedicarbonitrile‐2,4,5,6 tetrachloroisophthalnitrile) were applied as a foliar spray to plants at both sites. It was found that foliar injury symptoms were reduced greatly in plants treated with EDU and/or chlorothalonil, and the yield of treated plants was higher than that of the untreated ones, with the EDU having a greater protection than chlorothalonil. Antiozonant (EDU) and fungicide (chlorothalonil) combination sprays were even more effective in reducing O3 injury. Moreover, the percentage of protection was higher in the rural area than in the suburban one, and this was associated with higher levels of O3 recorded in the rural area. The response to O3, EDU, and chlorothalonil of the leaf antioxidant scavenger system was examined. Antiozonant‐treated plants had the highest reduced glutathione/oxidised glutathione ratio. The results suggest that EDU and chlorothalonil do not act directly as antiozonant to inhibit O3 injury but act through maintaining some antioxidant enzymes during O3 exposure. To the best of knowledge, this is the first report demonstrating the marked enhancement of yield and plant oxidative enzymes by fungicides as a mechanism of protecting plants against noxious oxidative stress from the environment in the developing world. |
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Keywords: | Chlorothalonil ethylenediurea glutathione reductase ozone (O3) peroxidase potato (Solanum tuberosum L. cv. Kara) superoxide dismutase yield |
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