Use of Legume-Microbe Symbioses for Phytoremediation of Heavy Metal Polluted Soils: Advantages and Potential Problems pp. 443-470
Authors: (V.I. Safronova, G. Piluzza, S. Bullitta, A.A. Belimov, All-Russia Research Institute for Agricultural Microbiology, St.-Petersburg, Russian Federation, and others)
Abstract: There is evidence that many legume species of the flowering plant family Fabaceae may be efficiently used in phytoremediation of heavy metal polluted soils, particularly for revegetation and phytostabilization of mine soils. For such purposes, a number of legume species were used and this chapter gives an updated glimpse on scientific experiences dealing with microbial effects on several legume species growing in heavy metal polluted soils. Legume species are able to form symbiosis with various beneficial microorganisms, such as nitrogen-fixing nodule bacteria, arbuscular mycorrhizal fungi and plant growth-promoting bacteria. Such plant microbe associations have implications in plant growth, nutrition and disease control. The symbioses between legumes and microorganisms provide nutrients for the plant, stimulate plant growth, exert antistress effects on plants, improve soil fertility, and restore ecosystem biodiversity and functions. This makes legumes very tempting subjects for phytoremediation purposes, particularly for the development of ecologically friendly phytostabilization technologies, since many of HM polluted soils are characterized by low nutrients and degenerated biocenosis. Moreover, symbiotrophic microorganisms possess a number of mechanisms which may be involved in improving tolerance of plants to environmental stresses, including those caused by heavy metals. As a consequence, the use of legume species for phytoremediation purposes should be considered in the context of their interactions with symbiothrophic microorganisms. Several plant species from the family Fabaceae and their performances in combination with microorganisms on heavy metal polluted soils or hydroponics are reported in this chapter. Particular attention is drawn on the effects of symbiotrophic microorganisms on legumes in the presence of heavy metals in conditions of monoinoculation and in combined inoculations. Intraspecific variability of plant species in their interactions with microorganisms is also discussed as well as the perspectives for phytoremediation with genetically modified legumes and symbiotrophic microorganisms. Successful attempts to increase tolerance to and accumulation of HMs by legume plants via genetic modifications and selection are mentioned. Although the presence of literature reports on the use of legume plants for phytoremediation purposes, it is undoubtedly wise to state that their potential for phytoremediation has not yet been adequately explored. Aim of this chapter is the discussion of advantages and problems in the application of legume-microbe systems for restoration and phytoremediation of polluted soils.
Open Access item.
Click below PDF icon for free download.
This is an Open Access item. Click above PDF icon for free download.