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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #155254
Title: RESPIRATORY COSTS OF MYCORRHIZAL ASSOCIATIONS

Author
item Bryla, David
item EISSENSTAT, DAVID - PENN STATE UNIVERSITY

Submitted to: Advances in Photosynthesis and Respiration
Publication Type: Review Article
Publication Acceptance Date: 12/18/2003
Publication Date: 8/1/2005
Citation: Bryla, D.R., Eissenstat, D. 2005. Respiratory costs of mycorrhizal associations. Advances in Photosynthesis and Respiration. In: Lambers, H., Ribas-Carbo, M., editors. Plant Respiration. From Cell to Ecosystem. Dordrect, N.L.: Springer.p.207-224.

Interpretive Summary: Mycorrhizal fungi are soil fungi that form symbiotic and often mutually beneficial relationships with the roots of most terrestrial plants. In this chapter we review current literature concerned with plant respiratory requirements for supporting this important plant-fungal association, and its effect on the overall plant carbon economy. Controlled studies indicate that mycorrhizal respiratory costs are considerable, consuming between 2 to 17% of the carbon fixed daily by photosynthesis, varying depending on the plant host and fungal species involved, the stage of mycorrhizal colonization, and the environmental conditions. Respiratory energy is required by the fungus for construction of new fungal tissue, for maintenance and repair of existing fungal tissue, and for cellular processes in the fungal tissue associated with the absorption, translocation and transfer of nutrients from the soil to the host plant. Additional respiration is also required by the host plant for stimulated root activity, and potentially for increased production of root biomass. Field studies of these important processes will eventually lead us to better understand how significant mycorrhizal fungi are to the total carbon budgets of natural and managed plant communities.

Technical Abstract: Mycorrhizal fungi form symbiotic and often mutually beneficial relationships with the roots of most terrestrial plants. In this chapter we review current literature concerned with plant respiratory requirements for supporting this important plant-fungal association, and its effect on the overall plant carbon economy. Controlled studies indicate that mycorrhizal respiratory costs are considerable, consuming between 2 to 17% of the photosynthate fixed daily, varying depending on the host and fungal species involved, the stage of colonization, and the environmental conditions. Respiratory energy is required by the mycobiont for construction of new intraradical and extraradical fungal tissue (including reproductive structures), for maintenance and repair of existing fungal tissue, and for cellular processes in the fungal tissue associated with the absorption, translocation and transfer of nutrients from the soil to the host. Additional respiration is also required by the host plant for stimulated root cellular processes, and potentially for increased production of root biomass. Field studies of these important processes will eventually lead us to better understand how significant mycorrhizal fungi are to the total carbon budgets of natural and managed plant communities.