detection techniques depend on recognizing characteristics like height, leaf area,
and pigmentation abnormalities (Israeli et al. 1995). Biochemical detection identifies various plant responses to physiological factors such as hormones, light,
carbon dioxide assimilation, and alteration of pigment synthesis (Shahijram et al.
2003; Peyvandi et al. 2009) and they can do it in early stages of the plant, reducing
economic losses. Molecular detection techniques are used to determine the genetic
fidelity of micropropagated species. Some of these techniques are the karyotypes
and molecular markers like RFLP, RAPD, AFLP, and SSR (Bairu et al. 2011).
15.3 Genetic Transformation of Plant Cells
Genetic transformation involves the introduction and integration of DNA into the
nuclear, mitochondrial, and chloroplast genomes. Genetic transformation methods
are classified into two types: the direct method when DNA is introduced in the
plant cells or tissues by imbibition, microinjection, electroporation, or ballistic and
the indirect method using the soil bacterium Agrobacterium tumefaciens to transfer
foreign DNA to the plant material (Naqvi et al. 2010; Barampuram and Zhang
2011). Strategies on secondary metabolite production using genetic transformation; to transfer and integrate foreign DNA into de plant genetic material,
increased expression of precursors of secondary metabolites, increased gene
expression limited by the metabolic pathway of interest, creation of a new metabolic pathway from an existing route, inhibit competitive routes or catalytic steps
of the metabolite of interest using antisense DNA or iRNA, handling regulatory
genes like transcriptional activators or repressors, selection of mutants for
production of secondary metabolites, and reorientation of secondary metabolite
production to organs or tissues of interest by using specific promoters.
15.3.1 Methods for Detecting Genetically Transformed Cells
15.3.1.1 Marker Genes
Once transformed, it is necessary to select cell lines that express the integrated
DNA. There are a number of marker genes that have been used in plant selection,
such as neomycin phosphotransferase (NPTII) that confers kanamycin resistance
and is the most used as a selectable marker gene for dicots. There are also other
systems based on glyphosate resistance or spectinomycin and the bar gene (Phosphinothricin acetyltransferase, PAT) that confers resistance to Phosphinothricin,
which is the active component of the herbicide Basta (Goldschmidt and Day 2011).
15 Plants as Bioreactors for Human Health Nutrients
427
and pigmentation abnormalities (Israeli et al. 1995). Biochemical detection identifies various plant responses to physiological factors such as hormones, light,
carbon dioxide assimilation, and alteration of pigment synthesis (Shahijram et al.
2003; Peyvandi et al. 2009) and they can do it in early stages of the plant, reducing
economic losses. Molecular detection techniques are used to determine the genetic
fidelity of micropropagated species. Some of these techniques are the karyotypes
and molecular markers like RFLP, RAPD, AFLP, and SSR (Bairu et al. 2011).
15.3 Genetic Transformation of Plant Cells
Genetic transformation involves the introduction and integration of DNA into the
nuclear, mitochondrial, and chloroplast genomes. Genetic transformation methods
are classified into two types: the direct method when DNA is introduced in the
plant cells or tissues by imbibition, microinjection, electroporation, or ballistic and
the indirect method using the soil bacterium Agrobacterium tumefaciens to transfer
foreign DNA to the plant material (Naqvi et al. 2010; Barampuram and Zhang
2011). Strategies on secondary metabolite production using genetic transformation; to transfer and integrate foreign DNA into de plant genetic material,
increased expression of precursors of secondary metabolites, increased gene
expression limited by the metabolic pathway of interest, creation of a new metabolic pathway from an existing route, inhibit competitive routes or catalytic steps
of the metabolite of interest using antisense DNA or iRNA, handling regulatory
genes like transcriptional activators or repressors, selection of mutants for
production of secondary metabolites, and reorientation of secondary metabolite
production to organs or tissues of interest by using specific promoters.
15.3.1 Methods for Detecting Genetically Transformed Cells
15.3.1.1 Marker Genes
Once transformed, it is necessary to select cell lines that express the integrated
DNA. There are a number of marker genes that have been used in plant selection,
such as neomycin phosphotransferase (NPTII) that confers kanamycin resistance
and is the most used as a selectable marker gene for dicots. There are also other
systems based on glyphosate resistance or spectinomycin and the bar gene (Phosphinothricin acetyltransferase, PAT) that confers resistance to Phosphinothricin,
which is the active component of the herbicide Basta (Goldschmidt and Day 2011).
15 Plants as Bioreactors for Human Health Nutrients
427