Chemistry Reference
In-Depth Information
address important issues in biology and offer unique genetic pools to be used for gene
technology programs leading to yield improvement of various crops under severe
environmental stresses. Recent studies have concentrated on the native plants and to
identify their critical salt or drought tolerance traits that could potentially be used in
improving agricultural crops. Some reports [146] have compared
Arabidopsis thaliana
with 11
wild relatives in response to salinity. Major differences in some physiological traits
including growth, water transport and ion accumulation were found, these differences can
be exploited in the genetics of salt stress studies. Modern techniques that have been adopted
to increase the resistance of crop plants to drought and salinity, including technologies of
molecular biology, genetic engineering and tissue culture, have fruited in establishing solid
basics to face the future challenges in the question of global food security [55, 110, 147-150].
Moreover, hopes are still in the minds of the decision makers and scientists to exploit the
genetic bank in wild plants and / or genetically engineered plants to clean contaminated
environments, and to deal with the pollution problems that arose due to the human
activities and after the expansion in the industrial and urban sectors [151]. Striking successes
have been achieved using genetic manipulation to improve the phytoremediation methods
to remove pollutants from the environment as a step leading to the restoration of habitats
[127]. Some reports [152] have indicated that using genetic engineering techniques is
possible to improve some physiological characteristics in plants like uptake, transport,
accumulation and tolerance of metals; such efforts could lead to create and develop
transgenic plants have the ability to remove heavy metals from the growth medium. Thus,
efforts using modern techniques and the identification of potentially genes for
transformation of target plants could be promising approaches in improving the efficiency
of these plants in the phytoremediation of contaminated environments. Some novel works
worth to be mentioned here, some researchers [153] used chloroplast transformation to
enhance the capacity of tobacco (
Nicotiana tabacum
) plant for mercury (Hg)
phytoremediation, such technique may also have application to other metals that affect
chloroplast function. Also, [128] have reported that wetland grasses and grass-like monocots
can be changed genetically to improve their remediation potential. Plant species involved in
these efforts are among those monocots genera in various families such as Poaceae,
Cyperaceae, Juncaceae, and Typhaceae. Fulekar and his collaborators [154] have reported
that plants such as
Populus angustifolia, Nicotiana tabacum
and
Silene cucubalis
have been
genetically engineered to provide enhanced heavy metal accumulation characteristic as
compared to the corresponding wild type plants. Other efforts in breeding plants having high
biomass production and superior phytoremediation potential were considered as an
alternative approach to deal with contaminants. The general productivity of plants is
controlled by many genes, and genetic engineering techniques to implant more efficient
accumulator gene into other plants have been suggested by many authors [115, 155]. Recently,
some authors [156] in their review have concluded that transgenic plants and associated
bacteria bring hope for a broader and more efficient application of phytoremediation for the
treatment of organic compounds like polychlorinated biophenyls (PCBs). Genetic modification
of plants may improve some phytoremediation mechanisms like phytoextraction,
phytotransformation, etc, and also improve the bacterial efficiency in biodegradation of those
