Perspectives of plant-associated microbes in heavy metal phytoremediation

Influence of Soil Chemistry and Plant Physiology in the Phytoremediation of Cu, Mn, and Zn

“…The bioavailability of trace metals is also altered by biological activity. The microbial community present in the rhizosphere can produce chelators for delivering key plant nutrients and can enhance the availability/mobility of trace metals in the soil (Rajkumar et al, 2012).…”

“…Plants and their associated microbial community can release compounds in the root/rhizosphere zone that play crucial roles in tolerance, sequestration, and transport of trace metals (Rajkumar et al, 2012), as summarized in Figure 3.…”

“…Endophytes are microbes that live inside plant tissues without causing harm to the host and can facilitate plant growth as well as increase resistance to pathogens, drought and herbivores (Rajkumar et al, 2012). Plant growth-promoting bacteria can be exploited for promoting plant biomass production and metal phytoremediation in contaminated soils (Andreazza et al, 2010;Kumari and Singh, 2011).…”

Phytoextraction of heavy metal polluted soils using Sedum plumbizincicola inoculated with metal mobilizing Phyllobacterium myrsinacearum RC6b

“…Recently, microbial mediated plant stress amelioration has emerged as an important component of metal stress management in plants and their role in improving plant growth and phytoremediation process in metal polluted soils has been well established (Rajkumar et al, 2013). It has been demonstrated that the inoculation of plants with metalresistant plant growth-promoting rhizobacteria (PGPR) play an important role in improving the efficiency of heavy metal phytoremediation Rajkumar et al, 2012). PGPR such as Azospirillum, Azotobacter, Achromobacter, Bacillus, Burkholderia, Gluconacetobacter, Pseudomonas and Serratia, have been known to improve plant growth through various mechanisms like production of phytohormones, siderophores and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, and solubilization of mineral nutrients (Rajkumar et al, 2008;Sheng et al, 2008;Ma et al, 2009).…”

“…However, the bioavailability of heavy metals in rhizosphere soils is considered to be an important factor that determines the efficiency of phytoextraction process. Metal tolerant microbes have been frequently reported in the rhizosphere of hyperaccumulators growing in metal polluted soils indicating that these microbes have evolved a heavy metal-tolerance and that they may play significant roles in mobilization or immobilization of heavy metals by excreting various metabolites including organic acids or extracellular polymeric substances (Rajkumar et al, 2012;Prapagdee et al, 2013;Sessitsch et al, 2013). Sedum plumbizincicola is one of the hyperaccumulators (Jiang et al, 2010) which has a remarkable capacity to withstand the metal stress in polluted soils and recent experiments have also demonstrated its potential for heavy metal phytoextraction (Wu et al, 2008).…”