Mineral Nutrient Acquisition in Nonmycorrhizal and Mycorrhizal Plants

1996

17 Lit. Ang.

Unselbständiges Werk

5943

200101809

Both, root-induced changes in the rhizosphere and colonization of roots by mycorrhizal fungi have marked influence on mineral nutrient acquisition by plants from soils. Depending on plant species and nutrional status of the plants, root exudation of organic acids, phenolics or phytosiderophores enhances mobilization of sparingly soluble mineral nutrients in the rhizosphere. Colonization of roots by endomycorrhizae (AM) and ectomycorrhizae (ECM) is widespread in soilgrown plants and increases the spatial availability of mineral nutrients in the soil thus enhancing host plant growth particularly onnutrient-poor soils. Carbon investment into below-grown plant parts can be important for mineral nutrient acquisition, by allowing root-induced changes in the rhizosphere (e.g.organic acid exudation) which may increase flexibility and specificity of the plant responses. Mycorrhizal colonization may ensure a higher longterm stability in which protection against metal toxicity and root pathogens may also be important components.