The total amount of DNA in the nucleus of a cell or in the organelles is called the "genome". The nuclear genome is contained in large linear DNA molecules called chromosomes, which vary in size and number in different plant species, consequently the size of the genome also varies among plant species (Table-1). The mitochondrial and chloroplast genomes are on the other hand in circular DNA in multiple copies in each organelle. However, this simple relationship does not always hold, which is known as the "C value paradox".
7% of the genes are associated with the signaling process, 3% with transport through the cells and another 6%. The vectors can also manipulate the expression of the introduced genes in the host; expression factors. The differential resistance of the plasmids allows wild-type and recombinant types to be separated.
The European Federation for Biotechnology defines biotechnology as "the integrated use of biochemistry, microbiology and engineering sciences to achieve technological (industrial) use of the capabilities of microorganisms, cultured tissue cells and their parts;. British biotechnologists defined biotechnology as “the use of biological organisms, systems or processes in manufacturing and service industries; whereas Japanese biotechnologists define it as a technology that uses biological phenomena to copy and produce various types of useful substances; The book entitled "Biotechnology: Building on Farmers' Knowledge 1996" defines biotechnology as "the use of indigenous and/or scientific knowledge to manage (parts of) microorganisms or cells and tissues of higher organisms so that they supply goods and services useful to humans , emphasize the importance of indigenous knowledge for the improvement and also the rights of tribes and farmers in
In vitro regeneration of genetically modified plant cells or tissues is a prerequisite for the success of plant genetic engineering protocols. Different components of inorganic salts perform different functions in plant growth and development (Table 3 & 4. Thermolabile substances to be added to the culture medium (already autoclaved) after filter sterilization of the solution.
With in vitro cultures, all the needs of the differentiating plant cell, both chemical and physiological, must be met by the culture vessel, the growth medium and the external environment (light, temperature, etc.). The growth medium must provide all the essential mineral ions required for growth and development, because all the biosynthetic abilities of cells grown in vitro may not mimic those of the parent plant, supplying additional. Plant growth regulators are critical media components in determining explant differentiation and the developmental pathway of plant cells and tissues in vitro (as well as in vivo). The relationship between auxin and cytokinin determines the differentiation of regenerants in vitro of shoots, roots, callus, somatic embryos, etc.
There is some degree of dedifferentiation (i.e. the changes that occur during development and specialization are reversed to some extent), both in morphology (the callus usually consists of unspecialized parenchymal cells) and in metabolism during callus formation. Root cultures can be generated in vitro from root tip explants of primary or lateral roots and can be grown on simple media. Regardless of the type of culture, the sustained regeneration of the whole plant in vitro and its establishment into a mature plant is the main goal of plant tissue culture (except those cultures used for commercial production of metabolites using cell suspension cultures or callus tissues). An explant or callus can produce plants by two morphogenetic pathways, namely 1) organogenesis 2) somatic embryogenesis.
Organogenesis is dependent on the inherent plasticity of the plant tissue and is regulated by changing components in the medium.
C-NH-(CH 2 ) 3 -C-COOH
DNA TRANSFER PROCESS
- SPLIT -END VECTOR (SEV) SYSTEM
The high recombination rate, which is believed to be a hallmark of replication by reverse transcription, is also considered an obstacle to the introduction of foreign genes into camv DNA. An obvious requirement for any gene to be expressed as a transgene in plants is that it be expressed correctly (or at least in a predictable manner). It is known that the most important determinant of gene expression (level, location and timing) is the region upstream of the coding region.
Any gene expressed in a transformed plant must have a eukaryotic promoter that will function in plants. This is an important factor because many of the genes to be expressed in plants, the Bt gene, reporter genes and selectable marker genes, etc., are of bacterial origin. Therefore, they must be cloned with a promoter that will drive their expression in plants. Transgenes must also have appropriate terminator sequences at their 3' end to ensure that transcription terminates at the correct position.
In addition to the basic need for the promoter to be able to drive expression of the gene in plants, there are other considerations to be taken into account such as promoter strength, tissue specificity and developmental regulations, etc. The most widely used promoter is used to drive expression of genes in plant transformation vectors is the promoter for the cauliflower mosaic virus 35 S RNA gene (35S promoter). This promoter is considered to be expressed in all tissues of transgenic plants (though not necessarily in all cell types).
Non-plant-derived systems are independent of normal plant processes, requiring the use of agricultural-scale inducers. The selection in such cases is based on the inclusion of a substance toxic to plants in the culture media. In addition to or as an alternative to selectable markers, reporter genes are used as markers in many plant transformation vectors.
Currently, only a small number of repoter genes that are widely used in lant transformation vectors (Table.3) should ideally be easy to test, preferably with a non-destructive testing system, and there should be little or no endogenous activity in the plant to be transformed. The world's population has grown from 2.5 billion to 6.1 billion over the past 50 years and is unlikely to stabilize before 2100, when another 3 billion people will live on Earth. The “green revolution” made it possible for the world's food supply to triple during the last thirty years of the 20th century.
Transgenic crops for high yield, better food quality, resistant to diseases and highly tolerant to environmental stresses have been developed and adopted by farmers in several countries. The success in producing plants has been widely achieved due to the totipotency of plants and the availability of the plant tissue culture protocols which can be easily coupled with genetic engineering protocols.
