Nutrient transport in mycorrhizas: structure, physiology and consequences for efficiency of the symbiosis

• Published in: Plant and soil 1994-02, Vol.159 (1), p.103-113, Article 103
• Main Authors: SMITH, S.E., GIANINAZZI-PEARSON, V., KOIDE, R., CAIRNEY, J.W.G.
• Format: Article
• Language: English
• Subjects: Adenosine triphosphatases; Agronomy. Soil science and plant productions; Biological and medical sciences; Economic plant physiology; Ectomycorrhizas; Fundamental and applied biological sciences. Psychology; Fungi; Hyphae; Life Sciences; Mycorrhizal fungi; Mycorrhizas; Phosphates; Plant nutrition; Plant roots; Plants; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); Vegetal Biology
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/BF00000099

Nutrient transport in mycorrhizas occurs across specialized interfaces which are the result of coordinated development of the organisms. The structural modifications give rise to large areas of either inter-or intra-cellular interface in which wall synthesis is frequently modified and in which altered distribution of membrane bound ATPases is important, particularly with respect to mechanisms that may be involved in bidirectional transfer of nutrients. Except in orchid mycorrhizas, net movement of organic carbon from plant to fungus occurs, complemented by mineral nutrient movement in the opposite direction. The general consensus is that sustained transfer at rates that will maintain the growth and development of the organisms requires increases in the rates at which nutrients are lost from the organisms; possible mechanisms for this are discussed. The transfer processes are essential in determining both plant and fungal productivity and an approach to calculating the efficiency of the symbiosis in terms of the expenditure of carbon (or of phosphorus) is discussed.