The relationship between water content, activity, and free amino acids inHelix pomatia L.

1975 ◽  
Vol 98 (2) ◽  
pp. 169-181 ◽  
Author(s):  
W. Wieser ◽  
M. Schuster

1984 ◽  
Vol 38 (2) ◽  
pp. 177-179 ◽  
Author(s):  
B.S. Chauhan ◽  
N.C. Desai ◽  
Ramesh Bhatnagar ◽  
S.P. Garg


2016 ◽  
Vol 46 (7) ◽  
pp. 1136-1141 ◽  
Author(s):  
Anderson Carlos Marafon ◽  
Flavio Gilberto Herter ◽  
Fernando José Hawerroth ◽  
Adriana Neutzling Bierhals

ABSTRACT: Storage and remobilization are considered key processes for the effective use of nitrogen in temperate fruit trees. As dormancy begins, storage proteins are synthesized, coinciding with a reduction in the levels of free amino acids. Consequently, as dormancy breaks, these storage proteins are degraded, and an increase in the concentrations of amino acids occurs, in order to support new growth. The objective of this study was to evaluate water content of different vegetative tissues (buds, bark, and bole wood), volume of xylem sap, and free amino acid concentrations of xylem sap, during winter dormancy of Hosui Japanese pear trees (VL). Plant material was obtained from the Embrapa Temperate Climate experimental orchard at Pelotas, in the state of Rio Grande do Sul, Brazil. Xylem sap was extracted from the branches with the aid of a vacuum pump, and the free amino acids were determined by gas chromatography, using the EZ kit: Faast GC/FID (Phenomenex). Water content of buds, as well as the volume of sap and concentrations of both aspartic acid and asparagine, substantially increased over time, reaching maximum values in the phase preceding sprouting.





Author(s):  
J. C. A. Craik ◽  
S. M. Harvey

Pelagic eggs and demersal eggs of teleosts both have osmotic concentrations similar to that of the maternal body fluids, less than half that of sea water. Pelagic eggs are buoyant because they contain such large quantities of this dilute aqueous fluid. While the demersal eggs of teleosts usually have a water content of 60–70%, the buoyant pelagic eggs of marine teleosts such as whiting, Norway pout, saithe, cod, haddock, turbot, dab, plaice, witch, long rough dab, halibut and sole typically have a very high water content (ca. 92 %) and a lipid content of 10–17% of egg dry weight. About 90% of the buoyancy of such eggs in sea water is caused by their high aqueous content, only about 10% being caused by lipid. The buoyant eggs of grenadier and ling have large oil globules and higher lipid contents, 27 and 35 % of dry weight respectively. Nevertheless, most of their buoyancy is provided by their high aqueous contents (89 and 81 % water). The high water content of pelagic eggs is brought about by a massive influx of water into the oocytes during meiotic maturation (ripening) after vitellogenesis but before ovulation. In cod and plaice, ripening is accompanied by a four- to five-fold increase in both water content and free amino-acids, and by a large influx of both potassium and sodium. In cod, free amino-acids contribute much more than these inorganic ions to the water influx and to the total osmotic concentration of the mature egg, but in plaice the relative contribution of inorganic ions approaches that of the free amino-acids.



2017 ◽  
Vol 63 (No. 10) ◽  
pp. 455-460 ◽  
Author(s):  
Pavlíková Daniela ◽  
Zemanová Veronika ◽  
Pavlík Milan

The objectives of this study were to analyse the relationship between the contents of elements and free amino acids (AAs) in fronds of As-hyperaccumulator Pteris cretica cv. Albo-lineata (PC) and non-hyperaccumulator Pteris straminea (PS) during reversible senescence. The time-course effect on senescence was also investigated. The two ferns were grown in a pot experiment with soil containing 16 mg As<sub>total</sub>/kg soil for 160 days. The contents of elements and AAs in both ferns and in individual sampling periods differed. The highest accumulation of elements and AAs was measured in PS fronds after 83 days; however, the accumulation of As, Ca, Cu, Fe, Mg, P and asparagin in PC fronds was highest after 160 days. The results of principal component analysis showed more rapid senescence of PS compared to PC. This was caused by changes in the relationship between the contents of elements (cofactors of metalloenzymes, stress metabolites) and AAs (transport of NH<sub>2</sub> group and stress metabolites). The hyperaccumulator plant (PC) was more resistant than the bioindicator plant (PS) to the conversion from reversible to irreversible senescence.



2015 ◽  
Vol 49 (7) ◽  
pp. 4245-4254 ◽  
Author(s):  
Sonja Milić ◽  
Jelena Bogdanović Pristov ◽  
Dragosav Mutavdžić ◽  
Aleksandar Savić ◽  
Mihajlo Spasić ◽  
...  


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