Genetic engineering of plants | class 12 скачать в хорошем качестве

Genetic engineering of plants | class 12

Aslam o alikum I am Hassam ur Rahman and I am teaching Fsc biology since 2014 .I am always trying to improve myself and provide best lecture to students.i am taking content for the lecture from authentic and relevant sources but human errors are possible . you are requested to please highlight the mistakes.My lectures are equally reliable for Fsc and mdcat students #visiblescience #mdcatbiology #alevelbiology #neetbiology #fscbiology #geneticengineering This lecture is about Genetic Engineering of Plants Traditionally, hybridization, the crossing of different varieties of plants or even species, was used to produce plants with desirable traits. Hybridization, followed by vegetative propagation of the mature plants, generated a large number of identical plants with these traits. Today it is possible to directly alter the genes of organisms. Transgenic plants carry a foreign gene that has been introduced into their cells so that they have new and different traits. Since a whole plant will grow from a protoplast, it is necessary only to place the foreign gene into a living- protoplast. A foreign gene isolated from any type of organism is placed in the tissue culture medium. High-voltage electric pulses can then be used to create pores in the plasma membrane so that the DNA enters. In one of the first procedures carried out, a gene for the production of the firefly enzyme luciferase was inserted into tobacco protoplast and the adult plants glowed when sprayed with the substrate luciferin (Fig. 23.12). Unfortunately, the regeneration of cereal grains from protoplasts has been difficult. Com and wheat protoplasts produce infertile plants. As a result, other methods are used to introduce DNA into plant cells with intact cell wall. In one technique, foreign DNA is inserted into the plasmid of the bacterium Agrobacterium, which normally infects the plant cells. A plasmid can be used to produce’ recombinant DNA. Recombinant DNA contains genes from different sources, namely those of plasmids and the foreign genes of interest. When the bacterium infects the plant the recombinant plasmid is introduced into the plant cells (Fig.23.12). In 1987, John C Sanford and Theodore M. Klein of Cornell University developed another method of introducing DNA into a plant tissue culture callusThey constructed a device, called the particle gun, that bombards a callus with DNA coated microscopic metal particles. Then genetically altered somatic embryos develop into genetically adult plants. Many plants including com and wheat varieties have been genetically engineered by this method.