The necessity of transgenic technology in sustainable production

Abstract

It has been more than half a century that plant geneticists and breeders have been trying to assemble a combination<br />of genes in crop plants, in order to make them as suitable and productive as possible. Plant transformation technology in<br />crop plants was first undertakenin the 1980s based on the ability of foreign gene integration into host plant genome and<br />regeneration of transformed plant cells into whole plants. Soon after, transgenic plants were to be grown by farmers.<br />Statistics show that farmers have started to cultivate genetically modified plants (GMPs) commercially since 1996.<br />Between 1996 and 2012, the total surface area of land cultivated with GM crops has increased from 2 million hectares<br />to more than 170 million hectares in 29 countries. To this extent, some concerns have been raised by ecologists and<br />consumer organizations in West European countries based on the possibilities of horizontal and vertical gene flow of<br />antibiotic or herbicide resistance from transgenic plants into human intestinal bacteria and some weeds via outcrossing,<br />respectively. Due to consumer and ecologist concerns, different approaches have been developed to eliminate marker<br />(and/or reporter) genes from the nuclear or chloroplast genome after selection. Some of these proposed methods are:<br />1. Replacing selectable markers with screenable ones.<br />2. Elimination of marker genes by co-transformartion followed by classic recombination and selection.<br />3. Excision of marker gene by some site-specific recombinases.<br />4. Separation of the transgene and selectable marker by transposable elements.<br />5. Avoiding gene pollution by chloroplasts genetic engineering followed by elimination of selectable marker.