الفهرس 
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Abstract
The objective of this study was to evaluate the impacts of different concentrations of copper sulphate, lead nitrate and mercuric chloride (24, 50, 75 µM forcopper , 45, 90, 120 µM for lead and 15, 29, 44 µMfor mercury) on morphological parameters (root and shoot length, fresh and dry weight and water content), biochemical constituents [photosynthetic pigments, phenolic compounds, antioxidant enzymes (catalase, polyphenol oxidase and peroxidise), free amino acids and protein synthesis] and structural and ultrastructural changes in bean seedlings (Phaseolus vulgaris cv. Giza 6) grown in peat moss.
Our findings show that all morphological parameters decreased as concentration of metals was increased as compared to control plants. Similarly, photosynthetic pigments (chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll and carotenoid) of bean plants declined progressively with increasing concentrations of the selected heavy metals. As expected, Phenolic compounds either free phenolic acids or cell wall-bound phenolics increased with increasing concentrations for all the metals studied.
The present results show thatthe increment of copper sulphate and lead nitrate concentration in the soil was associated with the enhancement in Catalase (CAT) activity. CAT activity increased in conjunction with low concentrations of Hg while decreased under higher levels. Activity of both Peroxidise (POD) and Polyphenol oxidase (PPO) stimulated with increasing doses of the studied metals.
In terms of free amino acids (FAA) content, cysteine, methionine, proline and glycine increased in the 4 day exposure to 44 µMHg by 53.8%, 26%, 18.5%, and 9.8% respectively. Upon lead stress ( 120 µM) in the last sampling period (12th day) FAAs like isoleucine, cysteine, methionine, alanine and glycine, representing 94.5%, 73%, 50%, 35.8% and 35% increased respectively. Increase of 101.4%, 69.6%, 60%, 46.3% and 39% was recorded in isoleucine, phenylalanine, cysteine, serine and alanine respectively, with respect to their controls under copper
stress (75 µM) at 12 day harvest. As for transmission electron microscopy photographs showed numerous ultrastrcturalmodifications.
Proteins with low molecular mass of 17 to 40 kDa were observed in the stressed conditions in our investigation. Since those proteins were newly synthesized under stress of the tested heavy metals it appears to belong to small heat shock proteins (12-40) kDa. No specific effect of the metals under study on protein profiles could be observed based on the SDS-PAGE results obtained in this study. Namely, all metals induced similar changes in protein patterns in bean leaves, suggesting that Hg, Cu and Pb share similar pathway to certain extent.
The objective of this study was to evaluate the impacts of different concentrations of copper sulphate, lead nitrate and mercuric chloride (24, 50, 75 µM forcopper , 45, 90, 120 µM for lead and 15, 29, 44 µMfor mercury) on morphological parameters (root and shoot length, fresh and dry weight and water content), biochemical constituents [photosynthetic pigments, phenolic compounds, antioxidant enzymes (catalase, polyphenol oxidase and peroxidise), free amino acids and protein synthesis] and structural and ultrastructural changes in bean seedlings (Phaseolus vulgaris cv. Giza 6) grown in peat moss.
Our findings show that all morphological parameters decreased as concentration of metals was increased as compared to control plants. Similarly, photosynthetic pigments (chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll and carotenoid) of bean plants declined progressively with increasing concentrations of the selected heavy metals. As expected, Phenolic compounds either free phenolic acids or cell wall-bound phenolics increased with increasing concentrations for all the metals studied.
The present results show thatthe increment of copper sulphate and lead nitrate concentration in the soil was associated with the enhancement in Catalase (CAT) activity. CAT activity increased in conjunction with low concentrations of Hg while decreased under higher levels. Activity of both Peroxidise (POD) and Polyphenol oxidase (PPO) stimulated with increasing doses of the studied metals.
In terms of free amino acids (FAA) content, cysteine, methionine, proline and glycine increased in the 4 day exposure to 44 µMHg by 53.8%, 26%, 18.5%, and 9.8% respectively. Upon lead stress ( 120 µM) in the last sampling period (12th day) FAAs like isoleucine, cysteine, methionine, alanine and glycine, representing 94.5%, 73%, 50%, 35.8% and 35% increased respectively. Increase of 101.4%, 69.6%, 60%, 46.3% and 39% was recorded in isoleucine, phenylalanine, cysteine, serine and alanine respectively, with respect to their controls under copper
stress (75 µM) at 12 day harvest. As for transmission electron microscopy photographs showed numerous ultrastrcturalmodifications.
Proteins with low molecular mass of 17 to 40 kDa were observed in the stressed conditions in our investigation. Since those proteins were newly synthesized under stress of the tested heavy metals it appears to belong to small heat shock proteins (12-40) kDa. No specific effect of the metals under study on protein profiles could be observed based on the SDS-PAGE results obtained in this study. Namely, all metals induced similar changes in protein patterns in bean leaves, suggesting that Hg, Cu and Pb share similar pathway to certain extent.
The objective of this study was to evaluate the impacts of different concentrations of copper sulphate, lead nitrate and mercuric chloride (24, 50, 75 µM forcopper , 45, 90, 120 µM for lead and 15, 29, 44 µMfor mercury) on morphological parameters (root and shoot length, fresh and dry weight and water content), biochemical constituents [photosynthetic pigments, phenolic compounds, antioxidant enzymes (catalase, polyphenol oxidase and peroxidise), free amino acids and protein synthesis] and structural and ultrastructural changes in bean seedlings (Phaseolus vulgaris cv. Giza 6) grown in peat moss.
Our findings show that all morphological parameters decreased as concentration of metals was increased as compared to control plants. Similarly, photosynthetic pigments (chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll and carotenoid) of bean plants declined progressively with increasing concentrations of the selected heavy metals. As expected, Phenolic compounds either free phenolic acids or cell wall-bound phenolics increased with increasing concentrations for all the metals studied.
The present results show thatthe increment of copper sulphate and lead nitrate concentration in the soil was associated with the enhancement in Catalase (CAT) activity. CAT activity increased in conjunction with low concentrations of Hg while decreased under higher levels. Activity of both Peroxidise (POD) and Polyphenol oxidase (PPO) stimulated with increasing doses of the studied metals.
In terms of free amino acids (FAA) content, cysteine, methionine, proline and glycine increased in the 4 day exposure to 44 µMHg by 53.8%, 26%, 18.5%, and 9.8% respectively. Upon lead stress ( 120 µM) in the last sampling period (12th day) FAAs like isoleucine, cysteine, methionine, alanine and glycine, representing 94.5%, 73%, 50%, 35.8% and 35% increased respectively. Increase of 101.4%, 69.6%, 60%, 46.3% and 39% was recorded in isoleucine, phenylalanine, cysteine, serine and alanine respectively, with respect to their controls under copper
stress (75 µM) at 12 day harvest. As for transmission electron microscopy photographs showed numerous ultrastrcturalmodifications.
Proteins with low molecular mass of 17 to 40 kDa were observed in the stressed conditions in our investigation. Since those proteins were newly synthesized under stress of the tested heavy metals it appears to belong to small heat shock proteins (12-40) kDa. No specific effect of the metals under study on protein profiles could be observed based on the SDS-PAGE results obtained in this study. Namely, all metals induced similar changes in protein patterns in bean leaves, suggesting that Hg, Cu and Pb share similar pathway to certain extent.
The objective of this study was to evaluate the impacts of different concentrations of copper sulphate, lead nitrate and mercuric chloride (24, 50, 75 µM forcopper , 45, 90, 120 µM for lead and 15, 29, 44 µMfor mercury) on morphological parameters (root and shoot length, fresh and dry weight and water content), biochemical constituents [photosynthetic pigments, phenolic compounds, antioxidant enzymes (catalase, polyphenol oxidase and peroxidise), free amino acids and protein synthesis] and structural and ultrastructural changes in bean seedlings (Phaseolus vulgaris cv. Giza 6) grown in peat moss.
Our findings show that all morphological parameters decreased as concentration of metals was increased as compared to control plants. Similarly, photosynthetic pigments (chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll and carotenoid) of bean plants declined progressively with increasing concentrations of the selected heavy metals. As expected, Phenolic compounds either free phenolic acids or cell wall-bound phenolics increased with increasing concentrations for all the metals studied.
The present results show thatthe increment of copper sulphate and lead nitrate concentration in the soil was associated with the enhancement in Catalase (CAT) activity. CAT activity increased in conjunction with low concentrations of Hg while decreased under higher levels. Activity of both Peroxidise (POD) and Polyphenol oxidase (PPO) stimulated with increasing doses of the studied metals.
In terms of free amino acids (FAA) content, cysteine, methionine, proline and glycine increased in the 4 day exposure to 44 µMHg by 53.8%, 26%, 18.5%, and 9.8% respectively. Upon lead stress ( 120 µM) in the last sampling period (12th day) FAAs like isoleucine, cysteine, methionine, alanine and glycine, representing 94.5%, 73%, 50%, 35.8% and 35% increased respectively. Increase of 101.4%, 69.6%, 60%, 46.3% and 39% was recorded in isoleucine, phenylalanine, cysteine, serine and alanine respectively, with respect to their controls under copper
stress (75 µM) at 12 day harvest. As for transmission electron microscopy photographs showed numerous ultrastrcturalmodifications.
Proteins with low molecular mass of 17 to 40 kDa were observed in the stressed conditions in our investigation. Since those proteins were newly synthesized under stress of the tested heavy metals it appears to belong to small heat shock proteins (12-40) kDa. No specific effect of the metals under study on protein profiles could be observed based on the SDS-PAGE results obtained in this study. Namely, all metals induced similar changes in protein patterns in bean leaves, suggesting that Hg, Cu and Pb share similar pathway to certain extent.
The objective of this study was to evaluate the impacts of different concentrations of copper sulphate, lead nitrate and mercuric chloride (24, 50, 75 µM forcopper , 45, 90, 120 µM for lead and 15, 29, 44 µMfor mercury) on morphological parameters (root and shoot length, fresh and dry weight and water content), biochemical constituents [photosynthetic pigments, phenolic compounds, antioxidant enzymes (catalase, polyphenol oxidase and peroxidise), free amino acids and protein synthesis] and structural and ultrastructural changes in bean seedlings (Phaseolus vulgaris cv. Giza 6) grown in peat moss.
Our findings show that all morphological parameters decreased as concentration of metals was increased as compared to control plants. Similarly, photosynthetic pigments (chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll and carotenoid) of bean plants declined progressively with increasing concentrations of the selected heavy metals. As expected, Phenolic compounds either free phenolic acids or cell wall-bound phenolics increased with increasing concentrations for all the metals studied.
The present results show thatthe increment of copper sulphate and lead nitrate concentration in the soil was associated with the enhancement in Catalase (CAT) activity. CAT activity increased in conjunction with low concentrations of Hg while decreased under higher levels. Activity of both Peroxidise (POD) and Polyphenol oxidase (PPO) stimulated with increasing doses of the studied metals.
In terms of free amino acids (FAA) content, cysteine, methionine, proline and glycine increased in the 4 day exposure to 44 µMHg by 53.8%, 26%, 18.5%, and 9.8% respectively. Upon lead stress ( 120 µM) in the last sampling period (12th day) FAAs like isoleucine, cysteine, methionine, alanine and
glycine, representing 94.5%, 73%, 50%, 35.8% and 35% increased respectively. Increase of 101.4%, 69.6%, 60%, 46.3% and 39% was recorded in isoleucine, phenylalanine, cysteine, serine and alanine respectively, with respect to their controls under copper
stress (75 µM) at 12 day harvest. As for transmission electron microscopy photographs showed numerous ultrastrcturalmodifications.
Proteins with low molecular mass of 17 to 40 kDa were observed in the stressed conditions in our investigation. Since those proteins were newly synthesized under stress of the tested heavy metals it appears to belong to small heat shock proteins (12-40) kDa. No specific effect of the metals under study on protein profiles could be observed based on the SDS-PAGE results obtained in this study. Namely, all metals induced similar changes in protein patterns in bean leaves, suggesting that Hg, Cu and Pb share similar pathway to certain extent.