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Start Over Coverage 353-359

1. Changes in CO2 exchange rate, stomatal conductance, activities of photosystems 1 and 2, and chloroplast polypeptide profile induced by simulated acidic rain

Creator:
Kumaravelu, G. and Ramanujam, M. P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
absorption spectra, chlorophyll fluorescence, photosynthesis, and Vigna radiata
Language:
Multiple languages
Description:
In seedlings of Vigna radiata (L.) R. Wilczek cultivars ADT-1 and CO-5 exposed to acidic showers (H2SO4 : HNO3 : HCl, 4 : 2 : 1, v/v) of different pH (7.0, 5.5, 4.0, and 2.5) for 10 d, net CO2 uptake and stomatal conductance were reduced. The chlorophyll (Chl) a and b contents were reduced but the carotenoid (Car) content increased. In vivo Chl a fluorescence patterns of both the cultivars were altered. No significant change in photosystem (PS) 1 activity was observed except at pH 2.5 where an inhibition was evident. By contrast, PS2 activities declined rapidly with increasing acidity. The room temperature absorption spectra of isolated chloroplasts showed very little changes. SDS-PAGE analysis revealed depletion of 23, 33, and 55 kDa polypeptides. Cultivar CO-5 was more sensitive to acidic rain than cv. ADT-1. and G. Kumaravelu, M. P. Ramanujam.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Effect of zinc deficiency on chlorophyll content, photosynthesis and water relations of cauliflower plants

Creator:
Sharma, P.N., Kumar, Nikhir, and Bisht, S.S.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
Cauliflower (Brassica oleracea L. var. botrytis) plants subjected to Zn defíciency showed decreased leaf water potential and transpiration rate, and increased leaf thickness, and accumulation of sugars and starch. Zn-deficient leaves also showed decreased photosynthetic rates (P^) and compensation irradiance and increased apparent quantum efficiency. Decrease in leaf chlorophyll (Chl) content due to Zn defíciency, though signifícant on fresh mass unit was insignifícant on leaf area unit. Decreased was not attributable to the effects of Zn defíciency on Chl content upto 51 d of treatment. Zn-defícient leaves showed an insignifícant decrease in photosynthetic O2 evolution at saturating irradiance and CO2 supply; signifícant decreases in P^, stomatal conductance and intercellular CO2 concentration when the leaves were supplied with CO2 at atmospheric concentration suggest that stomatal limitation contributes signifícantly towards decreased P^ in Zn-defícient leaves.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public