What are the advantages of cell engineering in the efficient utilization of medicinal plant resources?
As a means of scientific research, cell engineering has penetrated into all aspects of bioengineering and has become indispensable. supporting technologies. In the fields of agriculture, forestry, horticulture and medicine, cell engineering is making great contributions to mankind.
1. Food and vegetable production
The use of cell engineering technology for crop breeding is the aspect that has benefited mankind the most so far. China has reached the world's advanced level in this field. Through anther haploid breeding, it has cultivated nearly a hundred rice varieties or strains and about 30 wheat varieties. Among them, the new wheat varieties developed by the Henan Academy of Agricultural Sciences have excellent traits such as lodging resistance, rust resistance, and powdery mildew resistance.
In conventional cross-breeding, it usually takes 8 to 10 years to breed a new variety. Using cell engineering technology to culture hybrid anthers in vitro can greatly shorten the breeding cycle, usually 2 to 3 years earlier. years, and is conducive to the screening of excellent traits. The micropropagation technology introduced earlier is also widely used in agricultural production. Its technology is relatively mature and has achieved great economic benefits. For example, China has solved the problem of potato degradation, and Japan's Kirin Company has been able to mass-cultivate virus-free micro potato tubers as seed potatoes in 1,000-liter containers, realizing the automation of seed potato production. Through the genetic variation of plant somatic cells, various economically significant mutants are screened, which plays a role in the creation of germplasm resources and the selection and breeding of new varieties. High-quality tomatoes, cold-resistant flax, and new strains of rice, wheat, corn, etc. have been bred. It is hoped that this technology can improve the quality of crops and make them more suitable for human nutritional needs.
Vegetables are an indispensable component of the human diet. They provide the human body with essential vitamins, minerals, etc. Vegetables are usually propagated through traditional methods such as seeds, roots, tubers, cuttings or root divisions, with low chemical costs. However, plant cell engineering technology still has great potential in the introduction and breeding, the purification and rejuvenation of varieties, and some intermediate links in the breeding process. For example, when new vegetable varieties are introduced from abroad, they often only have a few seeds or a very small amount of roots, tubers, etc. at first. To carry out large-scale planting, large-scale proliferation must be carried out first, so micropropagation technology can be applied to rapidly expand the population in a short period of time. In the conventional breeding process, protoplast or haploid culture technology can also be applied to quickly reproduce offspring and simplify seed production procedures. In addition, plant genetic engineering technology can also be combined to improve vegetable varieties.
2. Garden flowers
The application of cell engineering technology in the production practice of fruit trees and forest trees is mainly micropropagation and virus removal technology. Almost all fruit trees suffer from viral diseases, and most of them are passed from generation to generation through vegetative reproduction. Virus-free test tube vaccine technology can effectively prevent viral diseases, restore species and accelerate reproduction. At present, the virus removal technology for in vitro seedlings of more than ten kinds of fruit trees, including bananas, citrus, hawthorn, grapes, peaches, pears, lychees, longans, and walnuts, has been basically mature. The micropropagation technology of virus-free banana in vitro seedlings has become one of the precedents for industrialization and commercialization. Because bananas are triploid plants, they must continue their offspring through asexual reproduction. Traditional methods generally use bud propagation, which is seriously susceptible to disease and has a low reproduction rate. The use of virus-free micropropagation technology not only improves the quality, but also increases the yield per mu by about 30%~ 50%, which is easily accepted by banana farmers.
In recent years, research on economic forest tree tissue culture technology has also received great attention. Using this technology, large areas can be planted years earlier than conventional methods. In particular, the seeds of some forest trees have a long dormant period, making conventional breeding very time-consuming. According to incomplete statistics, more than a hundred species of forest plant seedlings have been successfully studied in vitro, such as many species of Pinus, Eucalyptus, and Poplar, as well as Paulownia, Sophora japonica, Ginkgo, tea, palm, coffee, and coconut. Tree etc. Among them, eucalyptus, poplar and Douglas fir are used in large areas for production. Australia has achieved afforestation of eucalyptus in vitro seedlings, and 400,000 eucalyptus trees can be reproduced every year through sapling culture.
Plant cell engineering technology has revolutionized modern flower production. In 1960, scientists first used micropropagation technology to cultivate orchid callus into plants, and soon formed an industrialized production system based on tissue culture technology - the orchid industry. Now, there are more than 150 kinds of products on the world orchid market, most of which are in vitro seedlings obtained using rapid micropropagation technology.
Since then, market supply has been freed from the constraints of factors such as climate, geography, and natural disasters. So far, more than 360 species of flower test-tube seedlings have been reported. There are dozens of species that have been put into commercial production. China's research on carnations, roses, gladiolus, chrysanthemums, African violets and other varieties is relatively mature, and some have been commercialized, with a large number of products sold to Hong Kong, Macao and Southeast Asia.
3. Clinical Medicine and Drugs
Since scientists from the University of Cambridge in the UK first obtained monoclonal antibodies using animal cell fusion technology in 1975, many viral diseases that humans are powerless to do have encountered their nemesis. . Monoclonal antibodies can detect very subtle differences between strains of multiple viruses and identify bacterial species and subspecies. These are beyond the capabilities of traditional serum methods or animal immunity methods, and the diagnosis is extremely accurate and the misdiagnosis rate is greatly reduced. For example, a monoclonal antibody against hepatitis B virus surface antigen (HBsAg) is 100 times more sensitive than the best current antisera and can detect 60% of false negatives with antisera.
In recent years, the application of monoclonal antibodies can detect some extremely small tumor lesions that have no clinical manifestations and detect the location and area of ??myocardial infarction, which facilitates effective treatment. Monoclonal antibodies have been successfully used in clinical treatment, mainly for some viral diseases for which there are no specific drugs, especially for children with poor resistance. People are studying "biological missiles" - monoclonal antibodies as carriers to carry drugs so that the drugs can accurately reach cancer cells to avoid the side effects of chemotherapy or radiotherapy that kill normal cells and cancer cells together.
Monoclonal antibodies can accurately detect ovulation. A new generation of immunocontraceptives is also under development. The basic principle is to use sperm, egg zona pellucida or early embryos to prepare monoclonal antibodies. Inject them into women's bodies, and the body will produce an immune response to the sperm, thereby preventing pregnancy. effect. The increasing maturity of human in vitro fertilization technology has given humans a greater choice in reproductive activities, promoted eugenics and postnatal care, improved the quality of the population, and also brought good news to infertile patients or people who are not suitable for childbearing.
Biological drugs mainly include various vaccines, vaccines, antibiotics, biologically active substances, antibodies, etc., which are intermediate products or secretions of metabolism in organisms. In the past, vaccines were prepared from animal tissues, which resulted in low yields and was time-consuming. Now, through cell engineering or cell fusion methods such as culture and mutagenesis, not only the efficiency has been greatly improved, but also multivalent vaccines can be prepared, which can resist the invasion of more than two pathogenic bacteria at the same time. Using the same method, cell lines that can grow and divide for a long time under culture conditions and secrete certain hormones can also be cultured. In 1982, American scientists used mutagenesis and cell hybridization to obtain an in vitro cultured cell line that could continuously secrete interferon, which has now been applied.
4. Breeding excellent varieties
At present, technologies such as artificial insemination and embryo transplantation have been widely used in animal husbandry production. The comprehensive use of liquid nitrogen ultra-low temperature (-196 degrees Celsius) preservation technology for semen and embryos has greatly expanded the number and range of matings for excellent male animals and poultry, and has broken through the seasonal restrictions on animal mating. In addition, eggs and sperm can be separated from excellent female or male animals, fertilized in vitro, and then artificially controlled new fertilized eggs can be planted into the uterus of female animals with poor germplasm to breed new excellent individuals. By comprehensively utilizing various technologies, such as embryo segmentation technology, nuclear transfer cell fusion technology, and micromanipulation technology, to transform egg cells at the cellular level, it is possible to create new varieties such as high-yielding dairy cows and lean pigs. In particular, the establishment of stem cells has shown bright prospects.