Search

Start Over Language Multiple languages Data provider Academy of Sciences Library/Knihovna Akademie věd ČR

2143. Effect of 24-epibrassinolide on the photosynthetic activity of radish plants under cadmium stress

Creator:
Anuradha, S. and Seeta Ram Rao, S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
cadmium, carbonic anhydrase, carotenoids, chlorophyll, growth, nitrate reductase, photosynthesis, and radish seedlings
Language:
Multiple languages
Description:
The present study was conducted to study the effect of 24-epibrassinolide (EBL) on changes of plant growth, net photosynthetic rate, carbonic anhydrase (E.C. 4.2.1.1) and nitrate reductase (E.C.1.6.6.1) activities in the leaves of Raphanus sativus L. under the influence of cadmium (Cd) stress. Cd reduced plant growth, photosynthetic pigment levels, net photosynthetic rate and the activities of carbonic anhydrase and nitrate reductase. However seed application of EBL reduced the toxic effect of Cd on plant growth, pigment content, photosynthesis and enzyme activities. The studies clearly demonstrated the ameliorating effect of 24-epibrassinolide in mitigating the toxicity of Cd in plants. and S. Anuradha, S. Seeta Ram Rao.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2144. Effect of 28-homobrassinolide treatment on nickel toxicity in Brassica juncea

Creator:
Masidur Alam, M., Hayat, S., Ali, B., and Ahmad, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carbonic anhydrase, catalase, chlorophyll, leaf, nitrate reductase, peroxidase, proline, protein, root, and shoot
Language:
Multiple languages
Description:
Plants of Brassica juncea L. cv. T-59 were supplied with 50 or 100 µM nickel (Ni50, Ni100) at 10 d after sowing (DAS), and sprayed with 28-homobrassinolide (HBR) at 20 DAS. The plants treated with Ni alone exhibited reduced growth, net photosynthetic rate, content of chlorophyll, and the activities of nitrate reductase (E.C.1.6.6.1) and carbonic anhydrase (E.C. 4.2.1.1) at observed 40 DAS, whereas, the contents of peroxidase (PER), catalase (CAT), and proline were increased. However, the spray of HBR partially neutralized the toxic effect of Ni on most of the parameters. Moreover, the treatment of HBR in association with either of the Ni concentration boosted the contents of PER and CAT in leaves and that of proline both in leaves and roots. and M. Masidur Alam ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2145. Effect of 6-benzylaminopiirine and thidiazuron on photosynthesis in crop plants

Creator:
Chernyad´ev, I.I.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
The effect of cytokinins benzylaminopurine (BAP) and thidiazuron on photosynthetic rate and enzyme activities in sugar beet, pea, meadow fescue and reed fescue leaves was studied. Low concentrations (3-10 g nr3) stimulated the net photosynthetic rate, the activities of ribulose-l,5-bisphosphate carboxylase/oxygenase (RuBPCO) and other enzymes of the carboxylation phase of Calvin cycle, i.e. ribose phosphate isomerase and phosphoribulokinase, and the cycle including the NADP-glyceraldehyde phosphate dehydrogenase complex. On the contrary, there was no change in phosphoenolpyruvate carboxylase activity. In treated leaves the quantity of RuBPC increased along with increases in the level of total leaf proteins. Thus cytokinins act, probably, by specific altering of the synthesis of certain proteins. Inducing or stimulating the synthesis of essential proteins involved in photosynthetic processes, cytokinins cause changes in photosynthetic activity.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2146. Effect of a short photoinhibition stress on photosynthesis, chlorophyll a fluorescence, and pigment contents of different maize cultivars. Can a rapid and objective stress indicator be found?

Creator:
Lootens, P., van Waes, J., and Carlier, L.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chilling stress, high irradiance, low temperature, and Zea mays
Language:
Multiple languages
Description:
The effect of a short cold stress in combination with photoinhibition stress, similar to a low temperature and a high irradiance situation during early morning in the spring time, was examined on four maize cultivars common for Belgium, that differ in early vigour. After 1 h of 2 °C and 500 μmol(photon) m-2 s-1, quantum efficiency and maximum photosynthesis rate at saturating irradiance decreased on average by 11 and 8 %, respectively. For one cultivar, Magister, the decrease was the largest: by 23 and 10 %, respectively. For this cultivar it was combined with a decrease of the water vapour conductance after the stress. The decrease of Fv/F0 due to the cold/light stress was dependent on the cold tolerance (early vigour) of the cultivars. Fv/F0 changed with -45.5 and -40.2 % for the cultivars Ardiles and Banguy, respectively (cultivars with a less good early vigour) in comparison to -36.3 and -35.9 % for Fjord and Magister, which have a good early vigour. Also the ratio of total chlorophylls/total carotenoids changed in dependence on cold tolerance of the cultivars. For more cold tolerant cultivars, the relative amount of total carotenoids (x+c) was higher, indicating a higher protective state. Both the parameter Fv/F0 and the ratio of total chlorophylls to total carotenoids can be used to differentiate the cold tolerant cultivars from the cold non-tolerant ones. Fv/F0 has the advantage because its resolving power is larger and the measurement is less expensive than determination of the pigment ratio. and P. Lootens, J. van Waes, L. Carlier.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2147. Effect of abiotic stress factors on fluctuations in contents of malate and citrate and on malic enzyme activity in moss gametophores

Creator:
Rzepka, A., Rut, G., and Krupa, J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Hieracium, Mnium, NAD- and NADP-malic enzymes, Polytrichum, phosphoenolpyruvate carboxylase, and pyruvate orthophosphate dikinase
Language:
Multiple languages
Description:
Diurnal fluctuations in the contents of malate in gametophores of Polytrichum commune Hedw. and Polytrichum piliferum Hedw. were small. In gametophores of Mnium undulatum Hedw. and leaves of Hieracium pilosella L. significant differences were found in the accumulation of malate between day and night. However, no significant diurnal differences were found in the contents of citrate. High irradiance, desiccation, and submergence by water resulted in increases in daily fluctuations of malate, particularly in the gametophores of P. piliferum and leaves of H. pilosella. Accumulation of malate during night may show the adaptation of the studied species to unfavourable conditions caused by stresses. The change in activity of NADP-malic enzyme may characterize a response to stress factors. and A. Rzepka, G. Rut, J. Krupa.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2148. Effect of abscisic acid and blue radiation on photosynthesis and growth of pea plants

Creator:
Siedlecka, M. and Romanowska, E.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
The effect of abscisic acid (ABA) on the net photosynthetic rate the ribulose 1,5-bisphosphate carboxylase (RuBPC) and the phosphoenolpyruvate caiboxylase (PEPC) activities, the chlorophyll (Chl) content and growth of pea plants (Pisum sativum L.) grown under "white" (WR) or blue radiation (BR), were investigated. BR as compared to WR enhanced P^, the activities of examined enzymes, and Chl content. In špite of higher of the plants grown under BR, diy matter of their shoots was lower in comparison with WR. ABA-treated plants grown under both WR and BR showed reduction in Pn- ABA had no effect on the activities of both RuBPC and PEPC and the Chl content. Independent on the radiation quality, ABA reduced stem elongation, but did not affect the biomass of whole shoots.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2149. Effect of Acacia plantations on net photosynthesis, tree species composition, soil enzyme activities, and microclimate on Mt. Makiling

Creator:
Lee , Y. K., Lee, D. K., Woo, S. Y., Park, P. S., Jang, Y. H., and Abraham, E. R. G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Acacia mangium, Acacia auriculiformis, dehydrogenase, grassland, Imperata cylindrica, phosphatase, Saccharum spontaneum, triphenyl formazan, and 2.3.5-triphenyltetrazolium chloride
Language:
Multiple languages
Description:
To determine the effectiveness of rehabilitation on improving ecosystem functions, we examined net photosynthetic rate (PN), tree species composition, soil enzyme activities, and the microclimate (air and soil temperature, relative humidity) of an area on Mt. Makiling that has been rehabilitated and protected from fire for over 12 years. After it was last burned extensively in 1991, restoration was initiated by planting Acacia mangium and Acacia auriculiformis. We selected three areas to study in 2003. Two areas were rehabilitated with A. mangium and A. auriculiformis, and one was still dominated by Imperata cylindrica and Saccharum spontaneum. PN of A. mangium and A. auriculiformis showed significantly lower values than those of I. cylindrica and S. spontaneum. The Acacia plantations had more naturally regenerated tree species than the grassland. Additionally, more tree species appeared in the A. mangium plantation than in the A. auriculiformis plantation. Ficus spetica was present in all of the study sites. Dehydrogenase and phosphatase activities were significantly higher in soil under the Acacia plantations than under grassland. Grassland showed higher air temperature, relative humidity, and soil temperature as well as a larger variation per hour in these parameters compared to the Acacia plantations. The highest air temperature, relative humidity, and soil temperature were measured in April during the dry season. From the regression analysis, soil temperature was significantly correlated with air temperature. Hence plantations, as a rehabilitation activity for grassland, promote natural regeneration and stabilize the microclimate. This stabilization of the microclimate affects establishment and growth of naturally occurring tree species. and Y. K. Lee ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2150. Effect of ammonium/nitrate ratio on pak choi (Brassica chinensis L.) photosynthetic capacity and biomass accumulation under low light intensity and water deficit

Creator:
Shang, H. Q. and Shen, G. M.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
biomasa, fotosyntéza, biomass, photosynthesis, chlorophyll fluorescence, electron transport rate, nitrate reductase, NH4+, NO3-, stomatal conductance, water-use efficiency, 2, and 581
Language:
Multiple languages
Description:
We conducted a hydroponic experiment in order to study effects of the ammonium/nitrate ratio (0:15, 5:10, 7.5:7.5, and 10:5) on photosynthetic characteristics and biomass accumulation in Brassica chinensis under low light intensity and water stress. Results showed that net photosynthetic rate, transpiration rate, intrinsic water-use efficiency, stomatal conductance, intercellular CO2 concentration, effective quantum yield of PSII photochemistry, electron transport rate, and nonphotochemical quenching were lower in the treatment (low light intensity and water deficit) than those in the control, whereas stomatal limitation increased. Minimum fluorescence, maximal quantum yield of PSII photochemistry, and photochemical quenching were largely unchanged. Pigment contents first increased and then decreased as the ammonium/nitrate ratios were altered, with significant differences between treatment and control observed at all ratios except for 10:5. Biomass first increased slightly and then decreased both in treated and control plants. Results suggest that economic losses caused by extreme conditions can be minimized by a proper adjustment of the ammonium/nitrate ratio., H. Q. Shang, G. M. Shen., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public