Move over controversial transgenic crops. Plant breeders now have genome preparation technology for highly developed crop varieties.
Gene (genome) development methods, developed since the 1990s, largely remained in place until a pair of “molecular scissors” called CRISPR-Cas9 were discovered by two female biologists in 2012 Emmanuelle Charpentier of France and Jennifer Doudna of the USA. he won the Nobel Prize for Chemistry in 2020 for this.
Unlike transgenic technology, in which genes from other organisms are inserted to develop a better crop, the CRISPR-Cas9 method makes it possible to add, remove or modify genetic material. to add a beneficial character or remove a destructive one. It is considered largely safe because foreign genes are not used to alter a plant genome in most cases.
CRISPR-Cas9 can alter genetic material in the genome, as do other gene mutation mechanisms such as zing finger nucleases and Transcription-like effect nuclease. The difference is that the new method, adapted from a naturally occurring gene editing system in bacteria, makes the work more accurate and efficient, and is cheaper and faster.
The technology will help scientists to develop new varieties that are resistant to disease and high yield in a few weeks rather than a year or two taken in another way. The U.S. has already released dozens of crops for production, and another hundred are still in the lab. In 2016, Dupont Pioneer, which merged with Dow Chemical Company, invented a cosmetics blend that produces amylopectin – a sugar-like molecule used in processed foods, adhesives and high-gloss paper – by reversing gene coding for another starch called amylose. Low-nicotine tobacco, anti-brown mushrooms and fragrant moss have been developed for homes.
Crops have not yet been released for commercial cultivation in China, but preparation machines are being trained on rice, wheat, vegetables and fruits.
Gene editing tools, called Site Directed Nucleases (SDN) technology, identify a specific target sequence of DNA and cut the DNA in that location. For example, with CRISPR-Cas9, researchers create a small piece of RNA with a short series of ‘guides’ that attach to a specific location on the genome. The enzyme Cas9, also bound to the same RNA, acts as a scissors to create a cut in the DNA. Once the DNA is cut, the researchers have three choices.
First, in what is known as SDN-1, scientists use the cell’s own repair tools to make a brief insertion and removal of the existing genetic material. For the latter (SDN-2), they insert an additional DNA repair template to add or remove at the site to activate the draw you want. Foreign gene is not used in these methods. The third method (SDN-3) uses a gene from a related or unrelated sex or even a synthetic gene.
India is still deciding whether to allow gene preparation for better crops. “Indian scientists have argued that, since SDN-1 and SDN-2 do not use any foreign genes, the crop developed using these methods should be treated as crops. normal. Those developed using SDN-3 can be placed under GMO regulation, ”says Chinnusamy Vishwanathan, Chief Scientist and Head of the Department of Plant Psychology, Indian Agricultural Research Institute, Delhi.
Many research organizations, however, are already trying to use genome editing tools for crop development. Vishwanathan uses gene preparation to introduce salt tolerance (which helps crops grow in salt water) in a popular rice mix, MTU1010, grown over 3 million hectares in the east and head southern India.
MK Reddy, a scientist at the International Center for Genetic Engineering and Biotechnology, Delhi, has also been working in this field. “Too many years of cultivation have led to the accumulation of too many negative genes in the rice plant.” Reddy cites an example of genes that inhibit the tillering (or branching) of rice. “If I eliminated those genes, I would become more active,” he says.
Gene preparation can also help improve a plant’s innate immunity. When pathogens such as fungi invade the plant system, they activate its native immunity to survive inside the plant. This can be addressed with technology, Reddy adds.
Further, generation down the line, these plants show no signs of development. “The tools I put in place to edit the genome will be removed in the crop of the next generation,” he explains.
Most scientists in the field of biotechnology feel that gene modification can solve problems of reduced agricultural productivity and loss of arable land as well as issues arising from climate change in production. will be.