Assignment 7: Revised Wikipedia Assignment 12/15/15

https://en.wikipedia.org/wiki/Crotalaria_juncea

Phytoremediation on Crotalaria juncea

edit

There are several methods that have been shown to be effective as in decontamination and remediation of contaminated soils [1]. A highly applicable method of soil remediation known as phytoremediation has been specifically shown to be effective as when used in soils contaminated with heavy metals. Phytoremediation has been demonstrated to be effective as for correcting Crotalaria juncea found in soils contaminated with herbicides. The method of phytoremediation functions effectively in decontamination and remediation by using microorganisms and plants to remove, transfer, stabilize, or destroy harmful elements [2]Crotalaria juncea found in soils contaminated with herbicides revealed high phytoremediation capacity. In addition, phytoremediation is effective in removal of copper, which has been identified as a metal strongly present in the soil of Crotalaria juncea. 

Effects of Copper on Crotalaria juncea

edit

Cultivated soil high in copper levels has proven to be effective in increasing the growth of Crotalaria juncea. However, an excess of copper in plant tissues has demonstrated the potential of affecting both physiological and biochemical processesincluding photosynthesis [3]. Toxicity resulting from excessive copper has also resulted in altered effects that have been found to affect the cellular and molecular levels of the plant [4]. Excessive copper levels can ultimately result in depletion of necessary nutrients. This nutrient deficiency occurs when the interactions of copper with sulfhydryl groups of enzymes and proteins inhibit enzyme activity or result in changes in the structure or replacement of key elements [4]. The structures of chloroplasts have been affected by the excess of copper, which ultimately resulted in decreased pigmentation levels of Crotalaria juncea [5]. There are, however, studies that have indicated that Crotalaria juncea has a high tolerance to copper concentrations in the soil and root systems which are beneficial traits for phytostabilization programs [6].

Phosphate and Rhizophagus clarus Altering Crotalaria juncea

edit

Studies have also shown that phosphate and Rhizophagus clarus are capable in altering the physiological responses of Crotalaria juncea that is found in soil high in copper levels [7]. Phosphate has been demonstrated to be effective in reducing the level of toxicity in Crotalaria juncea, resulting in promotion of plant growth. When the application of phosphate is coupled with the inoculation of Rhizophagus clarus, the result is a synergistic effect that allows copper toxicity levels to be reduced through various mechanisms [7]. This ultimately allows for the increased growth of Crotalaria juncea in spite of having been cultivated in high levels of copper.

Another effective approach in decreasing the levels of copper in Crotalaria juncea is with the use of arbuscular mycorrhizal fungi (AMF) [7]. Phosphate uptake is significantly improved in the presence of AMF, which functions to effectively reduce the amount of available heavy metals [8]. The symbioses with AMF and soil supplementation of phosphate allows for the promotion growth of Crotalaria juncea. Despite the high levels of copper in the soil of Crotalaria juncea, mechanisms have been determined which can reverse the toxic effects of copper and allow for growth of the plant.

References

edit
  1. ^ Gerhardt, Karen E., Xiao-Dong Huang, Bernard R. Glick, and Bruce M. Greenberg (2009) Phytoremediation and Rhizoremediation of Organic Soil Contaminants: Potential and Challenges. Plant Science 176.1: 20-30. Web.
  2. ^ Souza LCF, Canteras FB, Moreira S (2014) Analyses of heavy metals in sewage and sludge from treatment of plants in the cities of Campinas and Jaguariuna, using synchrotron radiation total reflection X-rayfluorescence. Radiat. Phys. Chem. 95:342-345.
  3. ^ Kabata-Pendias, A, Pendias, H (2011) Trace Elements Soils and Plants. (4th ed.) CRC Press, Boca Raton, p. 534.
  4. ^ a b Kabała, Katarzyna, Małgorzata Janicka-Russak, Marek Burzyński, and Grażyna Kłobus (2008) Comparison of Heavy Metal Effect on the Proton Pumps of Plasma Membrane and Tonoplast in Cucumber Root Cells. Journal of Plant Physiology 165.3: 278-88. Web.
  5. ^ Ciscato, R. Valcke, K. van Loven, H. Clijsters, F. Navari-Izzo (1997) Effects of in vivo copper treatment on the photosynthetic apparatus of two Triticum durumcultivars with different stress sensitivity. Physiol. Plant, 100, pp. 901–908
  6. ^ Zancheta ACF , Abreu CA, Zambrosi FCB, Erismann NM. Lagoa AMMA (2011) Fitoextracao de cobre por especies de plantas cultivadas em sulocao nutritiva. Bragantia. 70(4):737-744.
  7. ^ a b c Ferreira, Paulo Ademar Avelar, Carlos Alberto Ceretta, Hilda Hildebrand Soriani, Tadeu Luiz Tiecher, Cláudio Roberto Fonsêca Sousa Soares, Liana Veronica Rossato, Fernando Teixeira Nicoloso, Gustavo Brunetto, Juçara Terezinha Paranhos, and Pablo Cornejo (2015) Rhizophagus Clarus and Phosphate Alter the Physiological Responses of Crotalaria Juncea Cultivated in Soil with a High Cu Level. Applied Soil Ecology 91: 37-47. Web.
  8. ^ Cornejo, Pablo, Sebastián Meier, Gilda Borie, Matthias C. Rillig, and Fernando Borie (2008) Glomalin-related Soil Protein in a Mediterranean Ecosystem Affected by a copper Smelter and Its Contribution to Cu and Zn Sequestration. Science of The Total Environment 406.1-2 (2008): 154-60. Web.