ISSN:
1573-5036
Keywords:
Amino acids
;
Barley
;
Carbohydrates
;
Exudates
;
Hordeum vulgare
;
Proteins
;
Salinity
;
Salt
;
Stress
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary The effects of salt stress on levels of soluble carbohydrate, amino acids and proteins in the shoots, roots and exudates of barley were studied under sterile conditions using balanced and unbalanced, high-salt solutions at −500, −1000 and −1500 kPa of osmotic stress. Moderate and severe stress with the unbalanced, high-sodium solutions proved toxic to barley, but plants exposed to the low-sodium, balanced solutions remained green and the stems remained turgid after 7 days of treatment. Both types of salinity increased the content of soluble carbohydrate in the shoots at all levels of stress and in the roots at −500 and −1000 kPa of stress. Carbohydrate in the exudates increased over 20-fold in response to balanced stress, but an apparent 3-fold increase in the exudates from the unbalanced treatments was not significant. Sucrose, glucose and fructose remained the principal sugars in the roots and shoots regardless of the type or intensity of stress, but their relative contents varied with treatment. Galactose, maltose, ribose and rhamnose were the major sugars in all exudates. Protein contents in the tissues fell at each level of balanced and unbalanced stress, but significant changes in protein were not detected in the exudates. Stress increased the size of the free amino acid pool in the shoots; however, it stimulated the reverse trend in the roots. With the exception of the −500 kPa low-sodium treatment, stress also induced a marked decline in the free amino acid content of the exudates, thus initiating a major limitation on the supply of a key group of metabolites in the rhizosphere.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02197717
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