Insert selected DNA sequences into plants

Christopher A. Cullis, director of biology, at Case Western Reserve University, USA, explains that this is the foundation for his controversial research results.

Cullis spent more than 40 years studying mutations in plants, most recently flax (Linum usitatissimum), found that: the environment not only helps to eliminate harmful and useless mutations through selection. natural, but also affect beneficial mutations.

Cullis published his findings in the International Journal of Genetics and Molecular Biology and republished in a visual experiment journal, where he was challenging other scientists to repeat his experiment.

Specifically, Cullis focused on mutations related to the appearance of a DNA sequence, called LIS-1, and presented ways that the environment affects these changes.

If someone climbed a towering car plug and took samples from the top and bottom of the tree, taking DNA analysis would show that they were not the same. Controversy comes from the idea that the environment changes organisms when they grow and changes take place over time.

However, this theory was accepted initially, but was eventually rejected by scientists who found sex or gamete cells through the DNA of animals that were unaffected by the effects of environment. This concept is assumed to be the same for plants, but Cullis's research is different.

In his second study, on three separate flax fibers (flexible fibers, short fibers, long fibers) of the Stormont Cirrus flax variety were grown in three separate environmental conditions.

Each fiber has been nourished over many generations under different conditions: The first flexible fibers were developed under controlled conditions, the first short fibers developed under weak nutritional conditions, and the fibers The first long was developed in nutrient-rich conditions.

The experiment showed that each fiber reacted to each environmental condition in different ways, corresponding to the environment that their ancestors once lived and developed. Flexible fibers grow higher than other fibers under controlled conditions; Short fibers grow higher than other fibers when under weak nutritional conditions, and long fibers grow best in nutrient-rich conditions.

All this information does not fully explain Cullis' claim that under the influence of the environment in a single generation can help select useful mutations .

In polymerase chain reaction (PCR) reaction of DNA. Through this process, researchers can see when a specific DNA sequence (in this case LIS-1) will appear or disappear.

When plastic fibers are grown in low nutrient conditions LIS-1 chains, which are already absent, appear and continue genetics for future generations. The presence of the LIS-1 series helps Cullis confirm the belief that the environment can help plants transform and preserve useful mutations, even within a generation.

This finding helps explain why the DNA on the palm tree is genetically different when comparing two specimens taken from the top and the stump. Young plant spokes grew at the beginning of the current branch, sprouting on meristem. Each new meristem will be different due to its impact on the genetic structure. And during the development of the spokes, the DNA at the top of the tree becomes increasingly different than the DNA at the base of the tree.

Due to the controversy surrounding Cullis' findings, many scientists are hesitant to accept them as true. Cullis recalled the first discovery, when Cullis thought: " If this is true, we can get plants to adapt better to the environment in the same generation ."

In practical applications, Cullis hopes to identify specific gene sequences responsible for the ability to withstand harsh environments and insert it into the DNA sequences of other plants so that they can also withstand the environment. hard.

This will bypass the current methods of genetic engineering in plants, including affecting specific DNA sequence sequences to control heat resistance, cold resistance, pest resistance, . and instead narrowing the effort into just one DNA sequence.

By inserting this DNA sequence into the plant, this crop will grow well in a specific harsh environment, scientists can assign this plant to have the ability to resist at will. All seedlings of this crop will also adapt well to growth. The cost of producing better seedlings will be significantly reduced. This will bring great benefits to developing countries, which need a large supply of food in harsh climatic conditions. The sequencing of DNA sequences not only helps plants survive, but can also help rural areas prosper.