relevant information from large data sets, presenting complex models in a more
manageable way and to propose efficient design metabolic networks. These
applications allow the design, reconstruction, and visualization of metabolic networks in silico; transformation vector design, protein engineering, metabolic flux
analysis, optimization, and automation of the culture conditions, and meanwhile,
creating databases that allow massive collection of information generated by omics
sciences (Copeland et al. 2012).
15.4.1 Strategies for Nutrient Production in Metabolic
Engineering
Human health depends entirely on plant foods. Plants are critical components of
the food chain providing nearly all essential mineral and organic nutrients in the
human diet directly or indirectly. However, plant foods do not contain all the
essential nutrients and do not meet sufficient amounts of daily food needs (Grusak
and Dellapenna 1999; Farré et al. 2011). The plant metabolites are important
because they change the quality, performance, resistance, and stress tolerance of
crops (Dixon 2005). These agronomic features of plants are controlled by complex
regulatory networks at multiple levels, where there is an interaction between
genes, such as in the case of synthesis of organic compounds in plants, mainly
primary and secondary metabolites, that represent an extensive group of interest,
due to characteristics and applications in the field of biotechnology. Based on the
previously described facts, a new era in plant biotechnology was reached by the
first successful genetic transformation of plants by A. tumefaciens (Herrera-Estrella et al. 1983), metabolic engineering used genetic engineering and molecular
biology tools to modify metabolic pathways in order to increase the concentration
of metabolites of interest (DellaPenna 2001). Because of the importance of food
with higher nutrient content, strategies began to be developed to increase vitamins,
lipids, and proteins in plants. Also steps are being taken to increase crop yield and
resistance to biotic and abiotic stresses. Unique gene introduction was the first
strategy for manipulating metabolic pathways. However, the results obtained were
not as expected. Multiple experiments dropped negative results and served to
highlight the complexity of metabolic pathways and their regulatory mechanisms.
Metabolic pathways are modulated in multiple levels and any disturbance may
affect the entire system, resulting in unexpected metabolite production (Verpoorte
and Memelink 2002). Because of this, the development of more complex and
sophisticated strategies involving multiple changes in the metabolic pathway have
come about. The strategies tried to insert more than one gene in the metabolic
pathway to carry out the production of a metabolite of interest (Capell and
Christou 2004). The negative regulation of gene expression was observed in
petunia, where the overexpressed chalcone synthase, which is important enzyme in
flavonoid synthesis, was expected to increase the concentration of anthocyanins.
But the result was the inhibition in the pigments synthesis; such regulatory
432
L. A. Cruz-Ramírez et al.
manageable way and to propose efficient design metabolic networks. These
applications allow the design, reconstruction, and visualization of metabolic networks in silico; transformation vector design, protein engineering, metabolic flux
analysis, optimization, and automation of the culture conditions, and meanwhile,
creating databases that allow massive collection of information generated by omics
sciences (Copeland et al. 2012).
15.4.1 Strategies for Nutrient Production in Metabolic
Engineering
Human health depends entirely on plant foods. Plants are critical components of
the food chain providing nearly all essential mineral and organic nutrients in the
human diet directly or indirectly. However, plant foods do not contain all the
essential nutrients and do not meet sufficient amounts of daily food needs (Grusak
and Dellapenna 1999; Farré et al. 2011). The plant metabolites are important
because they change the quality, performance, resistance, and stress tolerance of
crops (Dixon 2005). These agronomic features of plants are controlled by complex
regulatory networks at multiple levels, where there is an interaction between
genes, such as in the case of synthesis of organic compounds in plants, mainly
primary and secondary metabolites, that represent an extensive group of interest,
due to characteristics and applications in the field of biotechnology. Based on the
previously described facts, a new era in plant biotechnology was reached by the
first successful genetic transformation of plants by A. tumefaciens (Herrera-Estrella et al. 1983), metabolic engineering used genetic engineering and molecular
biology tools to modify metabolic pathways in order to increase the concentration
of metabolites of interest (DellaPenna 2001). Because of the importance of food
with higher nutrient content, strategies began to be developed to increase vitamins,
lipids, and proteins in plants. Also steps are being taken to increase crop yield and
resistance to biotic and abiotic stresses. Unique gene introduction was the first
strategy for manipulating metabolic pathways. However, the results obtained were
not as expected. Multiple experiments dropped negative results and served to
highlight the complexity of metabolic pathways and their regulatory mechanisms.
Metabolic pathways are modulated in multiple levels and any disturbance may
affect the entire system, resulting in unexpected metabolite production (Verpoorte
and Memelink 2002). Because of this, the development of more complex and
sophisticated strategies involving multiple changes in the metabolic pathway have
come about. The strategies tried to insert more than one gene in the metabolic
pathway to carry out the production of a metabolite of interest (Capell and
Christou 2004). The negative regulation of gene expression was observed in
petunia, where the overexpressed chalcone synthase, which is important enzyme in
flavonoid synthesis, was expected to increase the concentration of anthocyanins.
But the result was the inhibition in the pigments synthesis; such regulatory
432
L. A. Cruz-Ramírez et al.