Environmental Engineering Reference
In-Depth Information
homeostasis, which also includes regulation of the metal-induced reactive oxygen
species (ROS) signaling pathway. Generation and signaling of ROS plays an impor-
tant role in heavy metal detoxification and tolerance.
5 Conclusion
Heavy metal toxicity can severely hamper growth and development of a plants spe-
cies. This generally occurs due to with a number of physiological and anatomical
changes in the plant body. The devastating impact of heavy metals can be related
to ionic imbalance, metal toxicity, reduced gas exchange parameters (especially
photosynthetic rate), degradation of chloroplast and photosynthetic pigments, and
changes in plant water relations. Among anatomical changes, disintegration of par-
enchymatous tissue, reduced size of cells in different tissues, reduced root and stem
diameters, reduced leaf growth, and narrower xylem vessels are more important.
Moreover, there is a spatial accumulation of heavy metal in different organs, more
commonly in epidermal, parenchymatous and phloem tissues. However, tolerance
to heavy metals stress varies from species to species, and even within a same popu-
lation.
References
Ahmad MSA, Hussain M, Saddiq R, Alvi AK (2007) Mungbean: a nickel indicator, accumulator
or excluder? Bull Environ Contam Toxicol 78:319-324
Albering HJ, van Leusen SM, Moonen EJC, Hoogewerff JA, Kleinjans JCS (1999) Human health
risk assessment: a case study involving heavy metal soil contamination after the flooding of the
river Meuse during the winter of 1993-1994. Environ Health Perspect 107:37-44
Ali MB, Vajpayee P, Tripathi RD, Rai UN, Singh SN, Singh SP (2003) Phytoremediation of lead,
nickel, and copper by
Salix acmophylla
Boiss.: role of antioxidant enzymes and antioxidant
substances. Bull Environ Contam Toxicol 70:462-469
Ali MA, Ashraf M, Athar HR (2009) Influence of nickel stress on growth and some important
physiological/biochemical attributes in some diverse canola (
Brassica napus
L.) cultivars. J
Hazard Mat 172:964-969
Alia, Saradhi PP (1991) Proline accumulation under heavy metal stress. J Plant Physiol 138:504-
508
Alia P, Mohanty P, Matysik J (2001) Effect of proline on the production of singlet oxygen. Amino
Acids 21:195-200
Alloway BJ (1995) Heavy metals in soils. Springer, The Netherlands
Ambo-Rappe R, Lajus DL, Schreider MJ (2011) Heavy metal impact on growth and leaf asym-
metry of seagrass,
Halophila ovalis
. J Environ Chem Ecotoxicol 3:149-159
Anjana, Umar S, Iqbal M (2006) Functional and structural changes associated with cadmium in
mustard plant: effect of applied sulphur. Commun Soil Sci Plant Anal 37:1205-1217
Anju A, Saxena S, Sharma DK (2004) Tolerance and phytoaccumulation of chromium by three
Azolla
species. World J Microbiol Biotechnol 22:97-100
Ashraf M, Harris PJC (2004) Potential biochemical indicators of salinity tolerance in plants. Plant
Sci 166:3-16
