Growth and Nitrate Reductase Activity of Chlorella fusca Cells as Affected by Long Term Salinity

2003 ◽  
Vol 46 (3) ◽  
pp. 423-427 ◽  
Author(s):  
A.A. Shafea
2011 ◽  
Vol 74 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Elżbieta Sacała ◽  
Agnieszka Biegun ◽  
Anna Demczuk ◽  
Edward Grzyś

In this study, investigated were the effects of NaCl (60 mmol/dm<sup>-3</sup>) and NaCl supplemented with different salts (5 mmol/dm<sup>-3</sup> CaCl<sub>2</sub>, CaSO<sub>4</sub>, CaCO<sub>3</sub>, KCl), on growth of two maize varieties (Cyrkon and Limko). After 7 days of cultivation in nutrient solution the growth response to salinity of both maize varieties was similar. NaCl led to a dramatic decrease in growth of plants (approx. 50% reduction in fresh and dry weight of root, and 70% reduction in fresh weight of shoot). Addition of extra Ca<sup>2+</sup> or K<sup>+</sup> to nutrient solution containing NaCl did not definitely improve the growth parameters of maize. However, among the tested salts, CaCl<sub>2</sub> had a beneficial visual effect on maize seedlings. In other cases the plants showed noticeable symptoms of salt damage. In long term exposure to salinity (two weeks) growth of Cyrkon was more inhibited than Limko. Comparison of growth responses in short-term exposure to salinity (7 days) with long-term (14 days) showed that in Cyrkon variety the negative effects of NaCl were intensified and addition of CaCl<sub>2</sub> to salinized solution had not positive effects on growth. On the contrary, in Limko variety, there was a significant improvement in growth (especially in root dry weight). This fact indicates that during longer exposure to salinity Limko was able to adapt to those conditions. Salinity caused a significant decrease in leaf nitrate reductase activity (60% and 30% reduction respectively in Limko and Cyrkon). Addition of CaCl<sub>2</sub> to salinized nutrient solution resulted in greater enzyme inhibition in Cyrkon (50% decline in relation to plants grown under sole NaCl), and 30% increase in Limko. Inhibition of nitrate reductase activity did not cause a decrease in concentration of soluble protein in maize leaves.


Crop Science ◽  
1966 ◽  
Vol 6 (2) ◽  
pp. 169-173 ◽  
Author(s):  
L. E. Schrader ◽  
D. M. Peterson ◽  
E. R. Leng ◽  
R. H. Hageman

Crop Science ◽  
1982 ◽  
Vol 22 (1) ◽  
pp. 85-88 ◽  
Author(s):  
E. L. Deckard ◽  
N. D. Williams ◽  
J. J. Hammond ◽  
L. R. Joppa

Author(s):  
Xudong Zhang ◽  
Bastian L. Franzisky ◽  
Lars Eigner ◽  
Christoph‐Martin Geilfus ◽  
Christian Zörb

AbstractChloride (Cl−) is required for photosynthesis and regulates osmotic balance. However, excess Cl− application negatively interacts with nitrate ($${\mathrm{NO}}_{3}^{-}$$ NO 3 - ) uptake, although its effect on $${\mathrm{NO}}_{3}^{-}$$ NO 3 - metabolism remains unclear. The aim was to test whether Cl− stress disturbs nitrate reductase activity (NRA). A maize variety (Zea mays L. cv. LG 30215) was hydroponically cultured in a greenhouse under the following conditions: control (2 mM CaCl2), moderate Cl− (10 mM CaCl2), high Cl− (60 mM CaCl2). To substantiate the effect of Cl− stress further, an osmotic stress with lower intensity was induced by 60 g polyethylene glycol (PEG) 6000 L−1 + 2 mM CaCl2), which was 57% of the osmotic pressure being produced by 60 mM CaCl2. Results show that high Cl− and PEG-induced osmotic stress significantly reduced shoot biomass, stomatal conductance and transpiration rate, but NRA was only decreased by high Cl− stress. The interference of NRA in chloride-stressed maize is supposed to be primarily caused by the antagonistic uptake of Cl− and $${\mathrm{NO}}_{3}^{-}$$ NO 3 - .


2017 ◽  
Vol 199 (6) ◽  
pp. 863-873 ◽  
Author(s):  
Silvana Gomes dos Santos ◽  
Flaviane da Silva Ribeiro ◽  
Camila Sousa da Fonseca ◽  
Willian Pereira ◽  
Leandro Azevedo Santos ◽  
...  

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