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Start Over Creator Nedunchezhian, N.

1. Decline of photosynthetic pigments, ribulose-1,5-bisphosphate carboxylase and soluble protein contents, nitrate reductase and photosynthetic activities, and changes in thylakoid membrane protein pattern in canopy shade grapevine (Vitis vinifera L. cv. Moscato giallo) leaves

Creator:
Bertamini, M. and Nedunchezhian, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chlorophyll, donor side, electron transport, fluorescence, nitrate reductase, and photosystems 1 and 2
Language:
Multiple languages
Description:
In canopy shade leaves of grapevine (Vitis vinifera L. cv. Moscato giallo) grown in the field the contents of chlorophyll (Chl), carotenoids (Car), and soluble protein per fresh mass were lower than in sun leaves. RuBPC activity, in vivo nitrate reductase activity (indicator of nitrate utilisation), apparent electron transport rate, and photochemical fluorescence quenching were also significantly reduced in canopy shade leaves. When various photosynthetic activities were followed in isolated thylakoids, canopy shade leaves exerted a marked inhibition of whole chain and photosystem (PS) 2 activity. Smaller inhibition of PS1 activity was observed even in high-level canopy shade (HS) leaves. The artificial exogenous electron donors, DPC and NH2OH, significantly restored the loss of PS2 activity in HS leaves. Similar results were obtained when Fv/Fm was evaluated by Chl fluorescence measurements. The marked loss of PS2 activity in canopy shade leaves was due to the loss of 47, 43, 33, 28-25, 23, 17, and 10 kDa polypeptides. and M. Bertamini, N. Nedunchezhian.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Effect of iron deficiency induced changes on photosynthetic pigments, ribulose-1,5-bisphosphate carboxylase, and photosystem activities in field grown grapevine (Vitis Vinifera L. cv. Pinot noir) leaves

Creator:
Bertamini, M., Nedunchezhian, N., and Borghi, B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chlorophyll, fluorescence, electron transport, photosystems 1 and 2, proteins, and ribulose-1,5-bisphosphate carboxylase
Language:
Multiple languages
Description:
The effect of iron deficiency on photosynthetic pigments, ribulose-1,5-bisphosphate carboxylase (RuBPC), and photosystem activities were investigated in field grown grapevine (Vitis vinifera L. cv. Pinot noir) leaves. The contents of chlorophyll (Chl) (a+b) and carotenoids per unit fresh mass showed a progressive decrease upon increase in iron deficiency. Similar results were also observed in content of total soluble proteins and RuBPC activity. The marked loss of large (55 kDa) and small (15 kDa) subunits of RuBPC was also observed in severely chlorotic leaves. However, when various photosynthetic electron transport activities were analysed in isolated thylakoids, a major decrease in the rate of whole chain (H2O → methyl viologen) electron transport was observed in iron deficient leaves. Such reduction was mainly due to the loss of photosystem 2 (PS2) activity. The same results were obtained when Fv/Fm was evaluated by Chl fluorescence measurements in leaves. Smaller inhibition of photosystem 1 (PS1) activity was also observed in both mild and severely chlorotic leaves. The artificial electron donors, diphenyl carbazide and NH2OH, markedly restored the loss of PS2 activity in severely chlorotic leaves. The marked loss of PS2 activity was evidently due to the loss of 33, 23, 28-25, and 17 kDa polypeptides in iron deficient leaves. and M. Bertamini, N. Nedunchezhian, B. Borghi.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Effect of simulated acid rain on fixation, ribulose-1,5-bisphosphate carboxylase and nitrate and nitrite reductases in Vigna sinensis and Phaseolus mungo

Creator:
Muthuchelian, K., Nedunchezhian, N., and Kulandaivelu, G.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
In greenhouse experiments the efFect of simulated acid rain (mist of H2SO4) treatment on i'*C02 fixation, ribulose-l,5-bisphosphate carboxylase (RuBPC), nitráte reductase (NR) and nitrite reductase (NiR) activities in Vigna sinensis L. and Phaseolus mungo L. was investigated at different pH. Seedlings exposed to acidic mists of pH 5.6, 4.0 and 2.0 for 5 d showed significant reduction in *“*€02 fixation, RuBPC, NiR and especially NR activities. Sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) of crude leaf extracts of RuBPC indicated a significant loss of 55 and 15 kDa polypeptides at pH 2.0 in both the crop plants. The reduction in the RuBPC activity in seedlings grown under acidic mists correlated well with the CO2 fixation. NR activity was affected more than the NiR activity.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Effect of triacontanol in flooded Erythrina variegata seedlings. 1. Changes in growth, photosynthetic pigments and biomass productivity

Creator:
Muthuchelian, K., Murugan, C., Harigovindan, R., Nedunchezhian, N., and Kulandaveilu, G.
Format:
print
Type:
model:internalpart and TEXT
Subject:
carotenoids, specific leaf mass, saccharides, relative growth rate, proteins, plant height, leaf area index, leaf area, and chlorophyll
Language:
Multiple languages
Description:
Seedlings of Erythrina variegata Lam. exposed to flooding for 10 d showed significant reduction in height, growth rates (leaf area in plant, leaf area index, relative growth rate, and specific leaf mass), biomass, chlorophyli (Chl) and carotenoid contents, and thylakoid membrane organization. Application of triacontanol partially compensated these effects and promoted height, biomass and Chl content. Starch and sugar contents were significantly higher in leaves of flooded seedlings.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Effect of triacontanol in flooded Erythrina variegata seedlings. 2. Changes in 14CO2 fixation, and ribulose-1,5-bisphosphate carboxylase, photosystem and nitrate reductase activities

Creator:
Muthuchelian, K., Murugan, C., Harigovindan, R., Nedunchezhian, N., and Kulandaivelu, G.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
The effect of spraying triacontanol (Tria) solution (1 g m'^) on •'*C02 fíxation, ribulose-l,5-bisphosphate carboxylase (RuBPC), nitráte reductase (NR) and photosystem (PS) activities in waterlogged Erythrina variegata Lam. was investigated under field conditions. Seedlings exposed to flooding for 10 d showed a significant reduction in •‘♦CO2 fíxation, and in NR, RuBPC and PS2 activities. Electrophoretic analysis of thylakoid polypeptides indicated a significant loss of 47, 43, 33, 25, 23, 17 and 15 kDa polypeptides in flooded seedlings. However, the application of Tria partially ameliorated the effect of flooding and promoted the above activities. The site of flooding injury was at the oxidation site of PS2 prior to the hydroxylamine donating site and perhaps close or after the diphenylcarbazide donating site. The increase in the RuBPC activity in Tria-treated seedlings under flooding correlated well with the changes in CO2 fíxation rate.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Effect of water deficit on photosynthetic and other physiological responses in grapevine (Vitis vinifera L. cv. Riesling) plants

Creator:
Bertamini, M., Zulini, L., Muthuchelian, K., and Nedunchezhian, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
amino acids, chlorophyll, net photosynthetic rate, nitrate reductase, proline, protease, relative water content, and ribulose-1,5-biphosphate carboxylase
Language:
Multiple languages
Description:
The grapevine (Vitis vinifera L. cv. Riesling) plants subjected to water deficit were studied for changes in relative water content (RWC), leaf dry mass, contents of chlorophyll (Chl), total leaf proteins, free amino acids, and proline, and activities of ribulose-1,5-bisphosphate carboxylase (RuBPC), nitrate reductase (NR), and protease. In water-stressed plants RWC, leaf dry matter, Chl content, net photosynthetic rate (PN), and RuBPC and NR activities were significantly decreased. The total leaf protein content also declined with increase in the accumulation of free amino acids. Concurrently, the protease activity in the tissues was also increased. A significant two-fold increase in proline content was recorded. and M. Bertaminni ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. Effects of phytoplasma [stolbur-subgroup (Bois noir-BN)] on photosynthetic pigments, saccharides, ribulose 1,5-bisphosphate carboxylase, nitrate and nitrite reductases, and photosynthetic activities in field-grown grapevine (Vitis vinifera L. cv. Chardonnay) leaves

Creator:
Bertamini, M. and Nedunchezhian, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chlorophyll, electron transport, donor side, and photosystem 1 and 2 activities
Language:
Multiple languages
Description:
In leaves of field-grown grapevine, the contents of chlorophyll, carotenoids, and soluble proteins and the activities of ribulose-1,5-bisphosphate carboxylase (RuBPC) and nitrate (NR) and nitrite (NiR) reductases were decreased in phytoplasma-infected leaves, but the contents of soluble sugars and total saccharides were markedly increased. In isolated thylakoids, phytoplasma caused marked inhibition of whole chain and photosystem 2 (PS2) activities. The artificial exogenous electron donor, diphenyl carbazide, significantly restored the loss of PS2 activity in infected leaves. and M. Bertamini, N. Nedunchezhian.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Effects of phytoplasma infection on growth and photosynthesis in leaves of field grown apple (Malus pumila Mill. cv. Golden Delicious)

Creator:
Bertamini, M., Muthuchelian, K., Grando, M. S., and Nedunchezhian, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
amino acids, chlorophyll content and fluorescence, electron donor, nitrate reductase, photosystem, phytoplasma, proteins, ribulose-1,5-biphosphate carboxylase, sugars, and starch
Language:
Multiple languages
Description:
The contents of chlorophyll (Chl), leaf biomass, and soluble proteins were markedly decreased in phytoplasma infected apple leaves. Similar results were also observed for ribulose-1,5-bisphosphate carboxylase, 14CO2 fixation, and nitrate reductase activity. In contrast, the contents of sugars, starch, amino acids, and total saccharides were significantly increased in phytoplasma infected leaves. In isolated chloroplasts, phytoplasma infection caused marked inhibition of whole photosynthetic electron chain and photosystem 2 (PS2) activity. The artificial exogenous electron donor, diphenyl carbazide, significantly restored the loss of PS2 activity in infected leaves. Similar results were obtained when Fv/Fm was evaluated by in vivo Chl a fluorescence kinetic measurements. and M. Bertamini ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

9. High irradiance induced changes of photosystem 2 in young and mature needles of cypress (Cupressus sempervirens L.)

Creator:
La Porta, N., Bertamini, M., Nedunchezhian, N., and Muthuchelian, K.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
acclimation to irradiance, chlorophyll fluorescence, D1 protein, donor side, electron transport, photoinhibition, photosystem 2, and proteins
Language:
Multiple languages
Description:
Photoinhibition of photosynthesis was studied in young and mature detached sun needles of cypress under high irradiance (HI) of about 1 900 μmol m-2 s-1. The degree of photoinhibition was determined by means of the ratio of variable to maximum chlorophyll (Chl) fluorescence (Fv/Fm) and electron transport measurements. Compared with the mature needles, the young needles, containing about half the amount of Chl a+b per unit area, exhibited a higher proportion of total carotenoids (Car) as xanthophyll cycle pigments and had an increased ratio of Car/Chl a+b. The potential efficiency of photosystem (PS) 2, Fv/Fm, markedly declined in HI-treated young needles without significant increase of F0 level. In contrast, the Fv/Fm ratio declined with significant increase of F0 level in mature needles. In isolated thylakoids, the rate of whole chain and PS2 activity markedly decreased in young HI-needles in comparison with mature needles. A smaller inhibition of PS1 activity was observed in both needles. In the subsequent dark incubation, fast recovery was found in both needle Types that reached maximum PS2 efficiencies similar to those observed in non-photoinhibited needles. The artificial exogenous electron donors DPC, NH2OH, and Mn2+ failed to restore the HI-induced loss of PS2 activity in mature needles, while DPC and NH2OH significantly restored it in young needles. Hence, HI-inactivation was on the donor side of PS2 in young needles and on the acceptor side of PS2 in mature needles. Quantification of the PS2 reaction centre proteins D1 and 33 kDa protein of water splitting complex following HI-exposure of needles showed pronounced differences between young and mature needles. The large loss of PS2 activity in HI-needles was due to the marked loss of D1 protein of the PS2 reaction centre in mature needles and of the 33 kDa protein in young needles. and N. La Porta ... [et al.]
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Increased stability of thylakoid components in Vigna sinensis L. seedlings grown under ultraviolet-B enhanced radiation

Creator:
Nedunchezhian, N. and Kulandaivelu, G.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
Chloroplasts isolated from Vigna sinensis L, seedlings grown under cool íluorescent (control chloroplasts) and ultraviolet-B (UV-B)-enhanced íluorescent (UV chloroplasts) radiation, when incubated at 10, 20, 30 and 40 °C, showed large variations in the photosynthetic electron transport reactions. The overall electron transport activity in both control and UV chloroplasts incubated at 40 decreased rapidly. In contrast to this, at 30 the control chloroplasts got inactivated very rapidly during the 30 min of incubation while the UV chloroplasts showed high stability. A similar trend was also noticed at 20 “C. At 10 °C, although the rate of inactivation was slow, UV chloroplasts were more stable than control chloroplasts. A similar trend was noticed in photosystern (PS) 2 activity. In contrast to overall electron transport and PS2 reactions, PS 1 activity showed only marginal changes at all temperatures. The polypeptide profiles of chloroplasts exposed to UV-B iixadiation for 60 min at different temperatures revealed marked decreases in the level of the 23 and 33 kDa polypeptides in control chloroplasts while in UV chloroplasts these polypeptides were highly stable. In addition, UV chloroplasts contained several new polypeptides of both high and low molecular masses. The polypeptide partem indicated that higher photochemical activity of UV chloroplasts over the control chloroplasts could be due to stabilization of PS 2 core complexes by the new polypeptides induced under UV-B enhanced radiation.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public