Plant Physiology - Musienko M. M. 2001

Plant Physiology and Biotechnology: Achievements and Prospects for Development
Methods of Cultivating Isolated Cells, Tissues, Organs, and Plant Biotechnology

The term tissue culture method refers to the cultivation of isolated Cells, their structures, Tissues, and Organs in vitro under sterile conditions on artificial nutrient media. In recent years, researchers' interest in tissue culture has grown significantly. This is due to the increasing role of Cell cultures in fundamental research in plant physiology and Cytology, as well as the Structure/179.html">Practical Applications OF cellular technologies. Fundamental research on Cells and Tissues in vitro serves as a foundation that bridges various levels of investigation—from the molecular to the population level—which is critically important for studying various biological problems in whole plant organisms. This biological modeling method allows researchers to interpret data while excluding correlative relationships and whole-Organism effects. One of the fundamental principles of tissue culture is the extent to which in vitro conditions reproduce those close or identical to the environment experienced by The Cell on the parent plant in vivo.

The foundations of this method have a relatively recent history. Haberlandt (1902) first applied this method in the early 20th century while working with palisade parenchyma cells, aiming to cultivate this tissue from a single cell. Although his initial failure delayed progress with plant organisms for some time, research continued using animal models.

A crucial requirement for cultivating isolated plant tissues is the provision of nutrient media with the appropriate composition. In Ukraine, isolated ROOT culture was already widely used by M.H. Kholodny back in 1915, when he employed this method to discover The Biosynthesis of phytohormones in root tips, forming the basis for his theory of Tropisms. He continued to use this method in his later work.

In the 1930s, the works of the American scientist White and the French scientist Gautheret led to The Development of the modern method of plant Tissue and organ culture. White demonstrated that root Meristems can grow indefinitely if repeatedly transferred to a fresh medium.

Table 21. White's Nutrient Medium, (pH 5.5)

Table 22. Schenk and Hildebrandt Nutrient Medium, (pH 5.8)

Tomato root tip clones in his experiments were maintained for over 30 years (White, 1949). Gautheret is credited with refining the composition of nutrient media for cultivating undifferentiated tissues from various organs of monocots, dicots, and gymnosperms (Gautheret, 1959). Gautheret introduced various callus tissues into culture as pure clones. Systematic tissue culture work in the 1940s was conducted under the guidance of Academician M.O. Maksimov. In Ukraine, this research was organized in the laboratory of F.L. Kalinin (Kalinin, Sarnatska, Polishchuk, 1980).

It is well known that cells of various tissues, organs, and organisms function in vivo under specific metabolic conditions, which serves as the scientific basis for developing nutrient media of diverse compositions. Currently, more than a hundred such media have been formulated. Essential components of nutrient media include mineral Nutrition sources, specific macro- and micronutrients, CARBOHYDRATES, and BIOLOGICALLY ACTIVE SUBSTANCES that regulate Cell Division and differentiation. The compositions of the media most widely used in micropropagation technology are listed in Tables 21 and 22. The mineral composition, driven by the core physiological requirements of most plant tissues, remains highly stable. Modifications are achieved by adding various growth regulators, with the regulatory role of Auxins, Cytokinins, and their ratio being particularly important. At The current stage, this method addresses numerous problems in plant physiology and biotechnology. Specialized nutrient media also exist for cultivating tissue cultures of specific plant species, such as orchids:

All problems solved using the tissue culture method can be divided into three categories:

— the first is resolved based on epigenetic modifications of Genetic information and its gradual realization under in vitro cultivation conditions.

·the second category of problems is addressed by altering genetic information through mutagenesis. Solving plant biology problems on this basis is of exceptional importance because it involves obtaining new cell line strains of tremendous theoretical and applied interest, such as for cellular Selection.

·the third category of problems is solved via tissue culture through the transfer and integration of genetic information.

In recent years, the tissue culture method has been increasingly applied to study the effects of various extreme factors on plants and the interactions between PLANT CELLS AND pathogenic organisms. This method is also employed to investigate heterosis, the genetic incompatibility of two genomes, hybrid sterility in distant crosses, and the transplantation of cells, their parts, and even organs.