• Journal of Life Science
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• v.24 no.5
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• pp.558-566
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• 2014

Growth induced by cadmium (Cd) and ethylsalicylic acid (ESA) and the effect of ESA on rubisco/rubisco activase were studied in tobacco. The effect of denaturants on rubisco/rubisco activase was also investigated. In order to determine optimal concentration of ESA for growth of tobacco, tobacco was treated with $10^{-6}$-10 mM. It was found that its growth was the highest at $10^{-4}$ mM ESA. In the experiment using control, Cd treated group, ESA treated group, and Cd and ESA mixture group, ESA alone showed the highest growth and Cd showed the lowest growth. Cd treated group was the lowest in both rubisco/rubisco activase content and activity. ESA reduced the rubisco/rubisco activase content, but increased their activity. The activity of rubisco was inhibited by treating L-cysteine, urea, thiourea, ${\beta}$-mercaptoethanol, and EDTA other than guanidine-HCl in control group. L-cysteine, urea, thiourea, and guanidine-HCl treatments showed no change, but ${\beta}$-mercaptoethanol and EDTA increased rubisco activase activity. In conclusion, ESA inhibited the content of rubisco and promoted its activity, whereas promoted the content of rubisco activase and inhibited its activity. In addition, the content and activity of rubisco and rubisco activase inhibited by Cd were recovered by ESA. The activity of rubisco and rubisco activase by Cd and ESA was inhibited by the denaturant and the recovery of ESA inhibited by Cd was lost by the denaturant.

• Journal of Life Science
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• v.20 no.11
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• pp.1667-1674
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• 2010

Influence of nitrate on growth, chlorophyll content, content and activity of rubisco and rubisco activase of tobacco plant cultured on MS medium treated with cadmium in vitro was studied. In vitro growth and chlorophyll content reduced at 0.2 mM Cd was recovered by nitrate and this recovery was most significant at 80 mM nitrate. Rubisco content at 80 mM nitrate was more increased compared to that at other concentrations. A similar change was also shown in rubisco activity. These resultsindicate that the activation and induction of rubisco reduced by Cd were recovered by nitrate. The degree of intensity of 55 and 15 kD polypeptides identified as the large and small subunits of rubisco by SDS-PAGE analysis at 80 mM nitrate was significantly higher than that at other concentrations. The content and activity of rubisco activase at 80 mM nitrate was significantly increased than that at other concentrations. These data suggest that the recovery effects of rubisco by nitrate may be associated with rubisco activase.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.510-515
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• 2006

The influence of $N^6-benzyladenine$ (BA) on in vitro growth, chlorophyll, rubisco and rubisco activase were studied in tobacco. After 11 weeks of treatment of various concentrations of BA, the most pronounced effect on in vitro growth and chlorophyll was found at 2 ${\mu}M$ BA. Rubisco content increased with increasing concentrations of BA, but a point at 2 ${\mu}M$ BA was reached beyond which increasing concentrations of BA cause inhibition of this enzyme. Rubisco activity showed patterns of change similar to rubisco content. These data suggest that rubisco activity was associated with an amount of rubisco protein. Under the assumption that effects of BA on rubisco may be related to by rubisco activase, in addition to, its content and activity were determined. The rubisco activase content at 2 ${\mu}M$ BA was more increased than other treatments. A similar change pattern was also observed in activity of rubisco activase. These results suggest that the effects of the activation of rubisco by BA seem to be related with rubisco activase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.229-235
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• 2004

The influence of sucrose on in vitro growth, chlorophyll content, and rubisco/rubisco activase were studied in tobacco leaves. The most pronounced effect on in vitro growth and the chlorophyll content was found at 4% sucrose. The rubisco content increased with increasing concentrations of sucrose, but a point was reached beyond which the increasing concentrations of sucrose caused an inhibition of this enzyme. The rubisco activity showed patterns of change similar to the rubisco content. These data suggest that sucrose may have an affect on the activation and induction of rubisco and that sucrose can be both a positive effector and negative effector depend on its concentration. The degree of intensity of 55 and 15 kD polypeptides, which were identified as the large and small subunit of rubisco, respectively, by SDS-PAGE analysis at 4% sucrose was significantly higher than that of other treatments, indicating that sucrose had an effect on both subunits. We subsequently examined whether the rubisco content and activity of being induced by sucrose is associated with rubisco activase. The rubisco activase content at 4% sucrose was higher than that of other treatments. A similar change pattern was also observed in the activity of rubisco activase. The intensity of two 52 and 51 kD polypeptide bands at 4% sucrose was higher than that of corresponding bands of other treatments. The stimulatory and inhibitory effects of rubisco by sucrose seemed to be caused by rubisco activase.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.646-651
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• 2007

This investigation was performed to study the influence of Cd and nitrate on growth, and chlorophyll and photosynthetic enzymes in seedling of tobacco. Growth inhibition by Cd was not recovered by nitrate. Chlorophyll levels were reduced by Cd. The combination of Cd and low concentration of nitrate decreased the chlorophyll content compared to that in plants exposed only to Cd. Activity and content of rubisco at Cd treatment was significantly lesser than in plants receiving no treatment, These data suggest that rubisco activity was associated with an amount of rubisco protein, and that the activation and synthesis of rubisco is inhibited by Cd. Both the activity and content of rubisco decreased by Cd were more decreased by nitrate. A similar change pattern was also observed in activity and content of rubisco activase. These results suggest that Cd- and nitrate-induced changes of rubisco could be correlated with rubisco activase, and that nitrate was concerned in not only the activation and synthesis of rubisco directly, but also rubisco activase leading to a large change in rubisco.

• Journal of Life Science
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• v.22 no.6
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• pp.778-787
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• 2012

The influence of salicylic acid (SA) on growth, chlorophyll, and rubisco/rubisco activase and effect of denaturator on rubisco/rubisco activase activity were studied in tobacco plants grown in vitro with cadmium (Cd) treatment. In order to find out the optimum concentration of SA, tobacco plants treated with $10^{-6}$ mM - $10^2$ mM of SA were grown in MS medium for 9 weeks, respectively. The most pronounced effect on in vitro growth was found at $10^{-4}$ mM SA. Among the control (not treated with Cd and SA), SA, Cd, and Cd + SA, the growth and content of chlorophyll were in the sequence of Cd < Cd + SA < control < SA, and significantly higher at SA compared with others. Similar results were also observed in the content and activity of rubisco and rubisco activase. These data suggest that inhibitory effect by Cd was reversed by SA. These results also indicate that SA has a positive effect on Cd. The effect of denaturants on rubisco activity showed in the sequence of Cd < Cd + SA < control < SA. Rubisco activity was promoted by L-cysteine and ${\beta}$-mercaptoethanol, not by urea, thiourea, and guanidium-HCl. These data suggest that urea, thiourea, and guanidium-HCl are able to act as denaturator, and L-cysteine and ${\beta}$-mercaptoethanol are not. None of the five denaturants affected the activity of rubisco activase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.94-100
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• 2003

We studied the effect of cadmium on chlorophylls and rubisco activation in Canavalia ensiformis L. leaves. Chlorophyll levels were reduced by 5.0 ${\mu}$M Cd. Rubisco activity at 5.0 ${\mu}$M Cd was significantly smaller than that at no treatment. Rubisco Content showed patterns of change similar to rubisco activity. These data suggest that rubisco activity was associated with an amount of rubisco protein, and that the activation and induction of rubisco is inhibited by Cd. The degree of intensity of 50 and 14.5 kD polypeptides identified as the large and small subunit of rubisco by SDS-PAGE analysis at 5.0 ${\mu}$M Cd was significantly lower than that at control, indicating Cd had a e f-fect on both subunits. Under the assumption that effects of Cd on rubisco may be r elated to rubisco activase, in addition to, its activity and content we re determined . The rubisco activase activity at 5.0 ${\mu}$M Cd was more decreased than the control. A similar change pattern was also observed in content of rubisco activase. Remarkable differences in the intensitiy of both the 45 kD and 41 kD band were found between at control and Cd-treatment. These results suggest that the change in the levels of rubisco activase leads to a subsequent alter action of rubisco levels.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.453-460
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• 2005

This investigation was performed to study Cd toxicity and the influence of Ca on Cd toxicity in growth, and photosynthetic pigments and enzymes in tobacco. Cd inhibited both growth and level of chlorophyll, but the inhibition was compensated by the treatment of Ca. Especially, chlorophyll content was significantly increased by the combination of Cd and Ca treatment compared with Cd treatment alone. In addition, activity and content of rubisco by Cd treatment was also significantly lesser than the non-treated control. The highly reduced activity of rubisco was minimized by the combined treatment of Ca to Cd. Rubisco activase activity and content also showed a pattern of change similar to the rubisco level, suggesting that Cd- and Ca-induced changes of rubisco could be caused by rubisco activase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.100-106
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• 2001

This investigation was performed to study the influence of benomyl on photosynthetic pigments and enzymes in soybean leaves. Chlorophyll and pheophytin levels were reduced by benomyl 45 days after greening. These results indicate that chlorophyll a and b, and pheophytin must be controlled by benomyl. SDS-PAGE analysis showed that 50 and 14.5 kD polypeptides represented as large and small subunits of rubisco. In the both of these subunits, the band intensity of the control was significantly higher than that after benomyl treatment, indicating that these two subunits are affected by benomyl. Benomyl strongly inhibited both the activity and content of rubisco as its concentration was gradually increased. However, it remains unclear whether this reduction of rubisco level was due to a reduced level of rubisco activase. Two major polypeptides of 46 and 42 kD were identified as rubisco activase subunits by SDS-PAGE. The intensity of these two bands was shown to be higher in the control than after benomyl treatment. These results indicate that the rubisco decrease resulting from increased benomyl concentrations was caused by rubisco activase. A significant decrease in both the activity and content of rubisco activase by benomyl was also observed. There results suggest that the decrease in rubisco level caused by benomyl is accompanied by a decrease in both the activity and content of rubisco activase.

• ALGAE
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• v.18 no.2
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• pp.121-127
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• 2003

The pyrenoid ultrastructure and distribution of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase in the chloroplasts of Chlamydomonas reinhardtii was studied using the immunogold localization technology with electron microscopy. There were several tubular thylakoids invading in the pyrenoid matrix to form several spokewise channels. The connections between pyrenoid matrix and stroma of chloroplast were the partial of channels. The starch sheath surrounding the pyrenoid was separated into several parts by the connections in transection. Some thylakoids were packed together near the connections in one side of the pyrenoid. Those special structures might be used to transport substance between pyrenoid and stroma of chloroplasts. With the antibody raised against the large subunits of Rubsico from C. protothecoides, the result of the gold immunolocalization of Rubisco in Chlamydomonas reinhardtii showed most of the gold particles heavily labeled the pyrenoid matrix, as well as the starch sheath matrix, and very few in the stroma of chloroplasts. The gold particle density was 880.00 $\pm$ 164.32, 190.00 $\pm$ 152.39 and 9.60 $\pm$ 5.37 ${\mu}m^{-2}$ in pyrenoid matrix, starch sheath and stroma region of chloroplast respectively (background: 5.67 $\pm$ 1.53 ${\mu}m^{-2}$). 99.59% of the total Rubiscos was calculated to be concentrated in the pyrenoid matrix and starch sheath by spatial densities. The gold immunolocalization of Rubisco activase also showed that Rubisco activase was mainly concentrated in the periphery of the pyrenoid and the starch sheath (the density was as high as 229.69 $\pm$ 96.96 ${\mu}m^{-2}$). There were very few gold particles located in the stroma of chloroplasts. These results indicated that pyrenoid surface and starch sheath was the site for Rubisco activation and $CO_2$ fixation, which supported the suggestion that pyrenoids perform photosynthesis function.