Page 155 - phytochemistry general program

This is the stage of secondary metabolism and production of bioactive secondary
metabolites.

To study the structural growth it is best done at log phase (phase 3), while
studying the production of secondary metabolites is performed at stage 5.

Areas of Application of P.T.C.

There are many areas of practical applications of P.T.C. We will stress upon three
main areas of applications which are related to the study of medicinal plants.

Principal topics include the following:
I) Morphogenesis and plant propagation.
II) Production of important secondary metabolites and/or expensive biochemicals.
III) Biosynthetic pathways and biotransformation of secondary metabolites.

I)- Morphogenesis and plant propagation.
Morphogenesis is the biological process that causes a cell, tissue or organism to
develop its shape. The idea in this field is based on the theory of totipotency.
Manipulations of nutrients and environmental conditions induced the
undifferentiated cells to produce specialized cells, organs, embryos that could be

grown to mature plant that flowered and set seeds.
Small amount of tissue can be used to yield hundreds or thousands of genetically

identical plants in the continuous process.
The generation of normal plants from sterile callus cultures attracted the attention

to many possible applications such as:
1- Crop improvement by producing new varieties of plant for breeding programs by

the use of mutagens and chemical irradiations.
2- Production of pathogen and disease free clones, e.g. sugar cane resistant to

mosaic virus and potato plants free from virus -x have been selected in vitro.
3- To shorten the life cycles of some plants e.g. in Japan, anther cultures of
tobacco has been used to prepare new lines resistant to tobacco wilt, only two

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