E-ISSN 2090-0503 | ISSN 1687-7497
 

Original Research 


EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION

Manal M. Emam Hemat I. Khattab Nesma M. Helal.

Abstract
An experiment was conducted to assess photosynthetic responses, fluorescence emission spectra and total antioxidant capacity of two rice cultivars (Giza 177 & IET 1444) subjected to drought stress in the absence and presence of silicon (1.5 mM) or selenium (0.03 mM). Drought stress was imposed by withholding water for 10 days, until leaf rolling symptoms was observed. Fluorescence emission spectra of leaf extract excited at λ 243 nm, 337 nm and 435 nm has been estimated in blue, green, and red regions. The results showed that the fluorescence intensity is negatively related to leaf chlorophyll content, particularly to the intensity near the 680 nm region. Drought stress decreased the chlorophyll content of both cultivars. Such reduction was concomitant with increase in soluble sugar, soluble protein, amino acid contents, flavonoids and total antioxidant capacity particularly in IET 1444. A decline in chlorophyll content and the increase in red fluorescence emission of Giza 177 may be responsible for the sensitivity of this cultivar. The higher blue fluorescence emission (Ex.λ = 243 nm) in IET 1444 as compared to Giza 177 after withholding irrigation might be attributed to the participating of some phenolic compounds in mechanism of adaptation to water deficit. Exogenous application of Se or Si enhanced the drought tolerance of rice seedlings. The mechanism of defense was mediated by increasing some osmolytes particularly in roots of stressed seedlings, total antioxidant capacity particularly in shoots of IET 1444, decreasing leaf rolling symptoms and consequently lowering fluorescence chlorophyll emission spectra.

Key words: Drought, Rice, Leaf rolling, Osmolytes, Blue, Green, and Red fluorescence, Total antioxidant capacity


 
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Pubmed Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. Egypt. J. Exp. Biol. (Bot.). 2012; 8(2): 271-283.


Web Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. https://www.egyseb.net//?mno=186917 [Access: December 06, 2023].


AMA (American Medical Association) Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. Egypt. J. Exp. Biol. (Bot.). 2012; 8(2): 271-283.



Vancouver/ICMJE Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. Egypt. J. Exp. Biol. (Bot.). (2012), [cited December 06, 2023]; 8(2): 271-283.



Harvard Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal (2012) EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. Egypt. J. Exp. Biol. (Bot.), 8 (2), 271-283.



Turabian Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. 2012. EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY (Botany), 8 (2), 271-283.



Chicago Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. "EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION." THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY (Botany) 8 (2012), 271-283.



MLA (The Modern Language Association) Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal. "EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION." THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY (Botany) 8.2 (2012), 271-283. Print.



APA (American Psychological Association) Style

Manal M. Emam Hemat I. Khattab Nesma M. Helal (2012) EFFECTS OF SILICON OR SELENIUM ON PHOTOSYNTHETIC APPARATUS AND ANTIOXIDANT CAPACITY OF RICE PLANT GROWN UNDER DROUGHT CONDITION. THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY (Botany), 8 (2), 271-283.