ISSN:
1573-5036
Schlagwort(e):
allocation
;
beech
;
cysteine
;
Fagus sylvatica
;
glutathione
;
Laccaria laccata
;
methionine
;
mycorrhization
;
oak
;
phloem
;
Quercus robur
;
sulfate
;
sulfur
;
uptake
;
xylem
;
xylem loading
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Abstract Sulfur nutrition of plants is largely determined by sulfate uptake of the roots, the allocation of sulfate to the sites of sulfate reduction and assimilation, the reduction of sulfate to sulfide and its assimilation into reduced sulfur-containing amino acids and peptides, and the allocation of reduced sulfur to growing tissues that are unable to fulfill their own demand for reduced sulfur in growth and development. Association of the roots of pedunculate oak (Quercus robur L.) and beech (Fagus sylvatica L.) trees with ectomycorrhizal fungi seems to interact with these processes of sulfur nutrition in different ways, but the result of these interactions is dependent on both the plant and the fungal partners. Mycorrhizal colonisation of the roots can alter the response of sulfate uptake to sulfate availability in the soil and enhances xylem loading and, hence, xylem transport of sulfate to the leaves. As a consequence, sulfate reduction in the leaves may increase. Simultaneously, sulfate reduction in the roots seems to be stimulated by ectomycorrhizal association. Increased sulfate reduction in the leaves of mycorrhizal trees can result in enhanced phloem transport of reduced sulfur from the leaves to the roots. Different from herbaceous plants, enhanced phloem allocation of reduced sulfur does not negatively affect sulfate uptake by the roots of trees. These interactions between mycorrhizal association and the processes involved in sulfur nutrition are required to provide sufficient amounts of reduced sulfur for increased protein synthesis that is used for the enhanced growth of trees frequently observed in response to ectomycorrhizal association.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1004459523021
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