Today's biotechnology is the subject of close attention and interest among ordinary people. Multiple pseudo-scientific media publications scare people. Plant biotechnology is based on a concept that is not at all scary and absolutely natural. And this is a protoplast of plant cells. Realizing that this, having familiarized yourself with the methods of plant biotechnology, all the finds and achievements of progress will not seem so frightening to you.
Everything except the shell
The word "protoplast" is formed by the merger of the two Greek words πρῶτο + πλαστός, which in translation means the first and educated. For all plant cells, some L-bacteria and mycoplasmas, protoplast is the entire contents of the cell, with the exception of a dense wall formed mainly from cellulose. It is this wall that gives plant cells strength and shape, acting as a skeleton. By removing it, we get a cell with all its contents, covered with a soft membrane (plasmolemma) - this is a protoplast of a plant cell.
A bit of history
The term entered biological terminology in 1880 thanks to the great German botanist-microbiologist Johannes Ludwig Emil Robert von Hanstein (1822-1880). It was his work that laid the foundation for a whole branch of botany - plant embryology. Since then, the bioengineering industry has stepped forward. The merger of protoplasts, the first hybrid of two types of tobacco was received by American biologist Peter Carlson in 1972. But only in 1985, the mutant rice variety Mitsui bayosas No. 1 and the late Hatsuyumi rice variety, selected by Japanese biologists using protoplasts, were first registered.
Features and qualities
The specific properties of a plant cell without a shell are important for the plant in the processes of mitosis and meiosis. Only in the absence of a membrane does cell division and their differentiation into structural components of tissues occur. A feature of a protoplasmic cell is its totipotency (multiple capabilities). Cell protoplasts are capable of regenerating the membrane, and upon division, form a callus (a group of dedifferentiated cells), forming the whole organism. In addition, protoplast is a structure that actively exchanges with the environment (proteins, lipoproteins and nucleic acids). These features of protoplasts are also used by biotechnologists and genetic engineers.
Protoplast structure
A plant cell without a membrane, protoplast, is usually divided into protoplasm and cell membrane. Protoplasm includes:
- Hyaloplasm (colloidal system, consisting of 90-95% of water and a dispersed component - proteins, fats, carbohydrates, nucleic acids and dissolved inorganic compounds.).
- Nucleus (intracellular membrane structure with chromosomes).
- Organelles (mitochondria, cytoplasmic reticulum, Golgi complex, vacuoles, centrioles, ribosomes) and plastids (chloroplasts, leukoplasts or chromoplasts).
All organelles and plastids are considered derivatives of protoplast.
Movement and Functions
Protoplast is complex and very different for various plant tissues. In addition, its contents are constantly moving, either rotationally or streamingly, ensuring the transport of substances in the cell and facilitating metabolic processes. All cell life is concentrated in the protoplast. Cell life begins with it (during division), all life processes take place in it, and the life of a particular cell ends with it (dehydration and death).
Protoplast isolation
There are several ways to isolate protoplasts. It:
- Mechanical - the cell wall is cut, and the protoplast goes into the environment. Modern mechanical methods are quite diverse, but they all have drawbacks: low productivity, it is a highly labor-intensive and lengthy process.
- Enzymatic - protoplast excretion occurs using enzymes (cellulase, hemicellulase, pectinase). In this case, the protoplast is not damaged and not dehydrated. This is a quick and efficient way (up to 10 million protoplasts are released from 1 gram of tissue).
This process is divided into three stages: enzymatic processing, the actual isolation of protoplasts and their separation with damaged residues.
What's next?
After the isolation of cell protoplasts, they undergo cultivation, and then they are ready to work in the field of biotechnology. Regeneration and development of the plant occurs either by embryogenesis or by the formation of callus. The development of the body can be achieved by the addition of hormones (auxins and cytokinins), which induce the morphogenesis of the plant organism. And important factors in these processes are the species specificity of the object, the method of isolation of protoplasts and the density of their seeding, the composition of the seeding medium.
Construction object
Fields of application of isolated protoplasts in biotechnology include theoretical and practical aspects, namely:
- They allow to study the structure and chemistry of the cell wall itself during its destruction and synthesis.
- With their help, the properties of plasmalemma and the nature of transmembrane transport are studied.
- The possibility of soft selection of cell organelles and their study.
- The study of differentiation of totipotent cells, interactions of the nucleus and hyaloplasm.
- Obtaining and studying somatic hybrid cells.
- Introduction of foreign organelles into the cell structure.
- Study of the mechanism of transgenesis (introduction of foreign genes).
Plant genetic engineering
Modern science is working today on the following areas of bioengineering technologies in crop production:
- Obtaining plants resistant to various herbicides.
- Development of plant resistance to insect pests.
- Increase crop yields.
- Increasing crop resistance to adverse environmental conditions.
- Improving the efficiency of assimilation of trace elements by plants.
And this is not a complete list of the tasks that bioengineers of countries all over the world set themselves.
Some amazing facts.
Scientists are working on transferring the gene of the African plant Dioscoreophyllum cumminisii into strawberries or apples, which is responsible for protein synthesis thousands of times sweeter than sucrose. Since protein, and not carbohydrate, is responsible for the sweetness in this case, this is truly a find for all people with diabetes.
Blue chrysanthemums and roses, green lilies, purple tulips are flowers that today no longer surprise anyone. Arctic apples oranges are still out of the ordinary.
Already there are poplars that remove up to 91% trichlorethylene from the solution, and this is the main component of groundwater pollution. Scientists are working on the removal of plants that can absorb more carbon from the air and store them in the roots - this should reduce the rate of development of the greenhouse effect on the planet.
But we will treat diseases by eating bananas. There are already studies proving that when a modified pathogen is introduced into a young tree, tree cells synthesize the proteins of this virus. Thus, having bitten off such a banana, we can assume that you have introduced yourself a vaccine against this disease.
Golden rice, unlike ordinary rice, contains beta-carotene carbohydrate, as in carrots. For people where there is no vitamin A in food (essential amino acids), this is just a find.
The Pentagon (USA) in 2003 awarded biotechnologists who developed a pine variety that changes color when it comes into contact with toxic chemicals of a biological and anthropogenic nature.
All the achievements of science bring people both benefits and entail long-term changes in the ecosystem of the planet. That is why in all countries there are so many laws and institutions that control this industry. In Russia, the research base and the monitoring of their results is the Federal Institution “N. I. Vavilov Institute of General Genetics” RAS in St. Petersburg. And from July 1 of this year, mandatory registration of all genetically modified organisms and products was introduced in accordance with the law of the Russian Federation No. 358 of 03/03/2016. Changing nature, we need to remember that with it everything has already been invented and balanced long before us and our appearance on this planet. Caution in action is the priority and motto of modern genetic engineering.