Cichorium intybus (Suresh et al. 2005), phenol by Helianthus annuus (Jha et al.
2013). Phenol is the most important natural contaminant in environment through
coal conversion process, petroleum refineries, pesticides, and petrochemical products (Jha et al. 2020). As individuals learn about the dangers of the contaminants,
they can share their knowledge with others. However, the lack of resources available
to people in less developed countries can impact significantly how much of a
difference education can make. Often, individuals in less developed areas are more
focused on surviving day-to-day than on the possible long-term effects of hazardous
chemicals (Russell 2005). Moreover, the proficiency of plants to metabolize harmful
substances will rely on the biochemical properties of metabolizing enzymes and
different defensive mechanisms that may extend the plant tissue survival rate. In fact,
the results from a comparative study of peroxidase enzymes from HRs of Daucus
carota, Ipomoea batatas, and Solanum aviculare evidenced an interspecific divergence in the priority for chlorophenol and phenol among the peroxidases (de Araujo
et al. 2004). Also, peroxidase isozymes engaged in the degradation of phenol
compounds within a species may indicate the difference in substrate selection and
the efficiency catalytic activity of phenol metabolism (Coniglio et al. 2008). This is
considering that these investigations are essential in creating awareness about the
enzymatic mechanisms of pollutant remediation for choosing selective enzymes that
might be developed in large quantities and used as catalysts for breakdown of the
contaminants (Gonzalez et al. 2006).
2.3 Phytoremediation of Xenobiotic Compounds
The HRCs are known for their fast growth, high metabolic activity, and genetic as
well as biochemical stability have been exploited for studies on biotransformation of
various xenobiotics and were proven to be very effective (Giri and Lakshmi Narasu
2000). The detonating materials viz., TNT and hexahydro-1,3,5-trinitro-1,3,5-triazine are extensive environmental pollutants frequently identified as
sub-contaminants in the army training fields (Rylott et al. 2011). Degradation of
the exploding TNT to further components through Catharanthus roseus HRCs was
reported by Hughes et al. (1996). Similarly, the biotransformation of anthracene by
HRCs of Medicago sativa and found that the root concentration factors were higher
than that of whole plants (Paul and Campanella 2000). The well-organized nature of
HRCs offers additional benefits, making them further susceptible for growing in
large-scale levels using bioreactors to understand the mechanisms in detail.
Phytoremediation of DDT to DDD and DDE has been claimed using the cellsuspension cultures of Glycine max and Triticum aestivum (Arjmand and
Sandermann Jr 1985; Scheel and Sandermann 1977). The common remediation
pathway of DDT involves subtractive dechlorination to DDD followed by
dihydrochlorination to DDE. The DDE was evidenced to be further humiliated to
DDMU through a dechlorination reaction (Hay and Focht 1998; Quensen et al.
1998). According to Suresh et al. (2005), Cichorium intybus and B. juncea HRCs are
36
A. K. Moola et al.
2013). Phenol is the most important natural contaminant in environment through
coal conversion process, petroleum refineries, pesticides, and petrochemical products (Jha et al. 2020). As individuals learn about the dangers of the contaminants,
they can share their knowledge with others. However, the lack of resources available
to people in less developed countries can impact significantly how much of a
difference education can make. Often, individuals in less developed areas are more
focused on surviving day-to-day than on the possible long-term effects of hazardous
chemicals (Russell 2005). Moreover, the proficiency of plants to metabolize harmful
substances will rely on the biochemical properties of metabolizing enzymes and
different defensive mechanisms that may extend the plant tissue survival rate. In fact,
the results from a comparative study of peroxidase enzymes from HRs of Daucus
carota, Ipomoea batatas, and Solanum aviculare evidenced an interspecific divergence in the priority for chlorophenol and phenol among the peroxidases (de Araujo
et al. 2004). Also, peroxidase isozymes engaged in the degradation of phenol
compounds within a species may indicate the difference in substrate selection and
the efficiency catalytic activity of phenol metabolism (Coniglio et al. 2008). This is
considering that these investigations are essential in creating awareness about the
enzymatic mechanisms of pollutant remediation for choosing selective enzymes that
might be developed in large quantities and used as catalysts for breakdown of the
contaminants (Gonzalez et al. 2006).
2.3 Phytoremediation of Xenobiotic Compounds
The HRCs are known for their fast growth, high metabolic activity, and genetic as
well as biochemical stability have been exploited for studies on biotransformation of
various xenobiotics and were proven to be very effective (Giri and Lakshmi Narasu
2000). The detonating materials viz., TNT and hexahydro-1,3,5-trinitro-1,3,5-triazine are extensive environmental pollutants frequently identified as
sub-contaminants in the army training fields (Rylott et al. 2011). Degradation of
the exploding TNT to further components through Catharanthus roseus HRCs was
reported by Hughes et al. (1996). Similarly, the biotransformation of anthracene by
HRCs of Medicago sativa and found that the root concentration factors were higher
than that of whole plants (Paul and Campanella 2000). The well-organized nature of
HRCs offers additional benefits, making them further susceptible for growing in
large-scale levels using bioreactors to understand the mechanisms in detail.
Phytoremediation of DDT to DDD and DDE has been claimed using the cellsuspension cultures of Glycine max and Triticum aestivum (Arjmand and
Sandermann Jr 1985; Scheel and Sandermann 1977). The common remediation
pathway of DDT involves subtractive dechlorination to DDD followed by
dihydrochlorination to DDE. The DDE was evidenced to be further humiliated to
DDMU through a dechlorination reaction (Hay and Focht 1998; Quensen et al.
1998). According to Suresh et al. (2005), Cichorium intybus and B. juncea HRCs are
36
A. K. Moola et al.