The genetic engineering was established in the early 1970s and it has played an important role in the field of biology after decades of continuous progress and development.
Plant genetic engineering technology uses recombinant DNA technology to systematically transform and recombine biological genes by artificial "shearing" and "splicing" in vitro, and then insert and integrate into the recipient plant genome to reorganize. The gene is expressed in the recipient cell, so that the recipient plant obtains a new shape and breeds a new variety with high yield, multi-resistance and high quality.
The research and application of plant genetic engineering is flourishing around the world and is considered to be the hope of agriculture in the 21st century. It plays an important role in the new agricultural revolution.
1. Plant genetic engineering and its technologies
Based on human's goals and design, plant genetic engineering was conducted through split, integrate, splice, etc. in vitro to make the genetic material is recombined, and those features are then transferred to the plant through a specific vector (such as plasmid, phage, virus, etc.) intracellularly, and the expression of the required genes are expressed in cells. With this, a new plant type is created. Genetic engineering has a superior development space for improving plant traits, quality, increasing yield, and improving plant resistance to diseases, insects, and stress resistance. Therefore, its future development is extremely broad.
Plant engineering genetic technology has greatly expanded the gene pool available to plants, and it has become a reality to initiate directional mutation according to people's preset plans, which has brought huge changes in plant breeding (mainly in the following aspects: break reproductive isolation, making it creates conditions for broadening the available gene banks of plants, and providing new techniques for manipulating mutations; most of the genes used for genetic engineering breeding have been studied more clearly. The purpose of improving plants is clear, and the selection means is effective, so that it is possible to produce directional variation and directional selection; by improving some key traits of plants, the original promotion varieties will be improved to a large extent, not only can shorten the breeding period, but also make a comprehensive breakthrough in different ecological regions; with the deepening of understanding of genetic engineering, the cloning of new genes and the improvement of transgenic technology, and the targeted operation of multiple genes will also be possible, which is difficult to imagine in conventional breeding, and may lead to new "green" Revolution").
2. The possible risk and mechanism of genetically engineered plants
People have gradually realized that because the current level of science and technology can not accurately predict all the manifestations of plant genetic engineering, the safety of plant genetic engineering has attracted people's attention.
2.1. Possible risk of genetic engineering plants
(1) The threat of genetically engineered plants to environmental safety:
①The effect of insect-resistant genetically engineered plants on other organisms. The insecticidal effect of insect-resistant genetically engineered plants is non-selective. It can also kill beneficial insects or other organisms in the environment while killing pests. Even when their residues are degraded in the soil, they will also affect insects or microorganisms in the soil.
②Antiviral genetically engineered plants pose a risk of new viruses. At present, in genetic engineering of antiviral plants, most of the genes introduced into plants are sequences derived from the viral genome, and the most widely used are CP gene, MP gene and replicase gene.
③The potential threat of genetically engineered plants to the Earth's ecosystem. After the release of genetically engineered plants, gene drift is inevitable, which causes the transferred genes to be passed on to other crops. Metabolites of genetically engineered plants will spread to the external environment, causing a chain reaction.
(2) The harm of genetically engineered plants to human health:
①Genetically engineered plants may contain known or unknown toxins that are toxic to humans.
②Genetically engineered plants may contain known or unknown allergens, causing allergic reactions in the human body and even death.
③Genetically engineered plants produce certain nutrients or nutritional qualities that cause certain symptoms in the body.
④After the genetically engineered plant is eaten by humans, the food will pass the drug resistance gene to the pathogenic bacteria in the human body, which will make the body resistant.
2.2 The mechanism of genetic engineering plant to cause risk
(1). Genetic engineering causes mutations in DNA in plants. Genetic engineering introduces foreign genes into plant gene tissues, causing DNA mutations in plants. Different locations of foreign gene introduction may lead to changes in plant gene expression, enzyme expression, or in unknown growth and metabolism in plants, which may produce or polymerize certain harmful substances, thereby threatening human health.
(2). Genetic engineering causes plants to contain new proteins that directly or indirectly endanger human health. Plant genetic engineering introduces genetic information into plants, and this genetic information may come from any organism on the earth that allows plants to produce new proteins. This new protein may directly harm human health or this new protein affects plant cell metabolism and changes the nutrient composition of the plant, thereby affecting human health.
(3). The harm may be caused by the unpredictability of genetic engineering. Although DNA can be spliced very accurately under laboratory conditions, the effect of a foreign gene into a plant on the entire plant genome cannot be fully predicted and controlled. The plant is an extremely complex living system, and our existing scientific knowledge and technical means cannot fully control the inheritance of plants.
3. Suggestions on improving the safety management of plant genetic engineering
(1). Have a full understand on the strategic significance of genetic engineering safety management, and improve the safety awareness of genetic engineering of all people, especially leading cadres and related scientific research and staff, and popularize relevant laws and regulations on genetic engineering safety management.
(2). Formulate a comprehensive "Genetic Engineering Law" to ensure that all laws and regulations on the safety management of genetic engineering are available.
(3). Establish an effective and timely genetic engineering supervision and reporting system, and conduct long-term follow-up monitoring of projects with higher risk levels to ensure that genetic engineering safety is within the controllable range.
(4). Establish a scientific genetic engineering risk assessment mechanism and explore the establishment of an authoritative genetic engineering risk assessment social organization. Strengthen the approval of research, development, promotion, import and export, and extend the review time of high-risk projects.
With the rapid development of plant genetic engineering technology, the emergence of new gene introduction technology (such as CRISPR/CAS9, TALEN-Mediated DNA Insertion, Virus-induced Gene Silencing etc.)and the technology of crop tissue culture are more convenient and effective. In the near future, it is expected to produce high-yield, high-quality, high-efficiency, disease-resistant, insect-resistant and anti-adversity crops. A new crop variety with excellent traits will benefit human beings and become an important weapon for human beings to understand nature and transform nature. At the same time, when seeing the achievements of genetic engineering plant, we must also see the risk of genetically modified plants.