Tissue culture techniques of higher plants refer to techniques for isolating one or several individual cells or a part of a plant body for cultivation.
Generally speaking, we refer to a generalized tissue culture in which a part of a plant body (i.e., an explant) is isolated by aseptic processing, inoculated on a medium, and cultured under artificially controlled conditions to produce a complete plant.
Image: plant cell culture
Physiological basis of plant cell culture
Cell totipotency: Each cell of a plant carries a complete set of genomes and has the potential to develop into a full plant.
Plant growth regulating substances play a key role in the differentiation and determination of plant cell tissues. It includes: auxins, cytokinins, gibberellins, abscisic acid, ethylene, and the like.
Auxins are mainly used for the formation of callus, the production of somatic embryos and the rooting of test-tube seedlings. Commonly used auxins are 2,4-D, NAA (naphthaleneacetic acid), IBA (indolebutyric acid), IAA (indole acetic acid) and the like. Its effect is 2,4-D>NAA>IBA>IAA.
Cytokinins promote cell division and differentiation, delay tissue aging, and promote bud production. Commonly used cytokinins are Zip, KT (clopidogrel), 6-BA (6-benzylaminoadenine), ZT (zeatin) and others. The order from strong to weak is Zip>KT>6-BA>ZT.
Gibberellin promotes the growth of differentiated shoots and breaks the dormancy of seeds. Commonly used gibberellin is GA3.
Types of plant cell culture
Tissue culture can be divided into tissue or callus culture, organ culture, plant culture, cell and protoplast culture according to the culture target.
- Tissue or callus culture is a tissue culture in a narrow sense, which is to cultivate various parts of the plant, such as shoot tip meristem, formation layer, xylem, phloem, epidermal tissue, endosperm tissue and thin wall tissue, etc.; or culture of callus produced by plant organ culture, both of which are induced to form plants by re-differentiation.
- Organ culture, namely the culture of isolated organs, depend on the crop and needs, may include isolation of shoot tips, stem segments, root tips, leaves, leaf primordia, cotyledons, petals, stamens, pistils, ovules, embryos, ovary, or fruits culture of explants.
- Plant culture is the cultivation of intact plant material, such as seedlings and larger plants.
- Cell culture is a culture of ex vivo single cells or pollen single cells or small cell clusters which can maintain good dispersibility by liquid shaking culture of callus or the like.
- Protoplast culture is the cultivation of protoplasts that remove cell walls by
enzymatic and physical methods.
Characteristics of plant cell culture
Tissue culture is a new technology developed in this century. Due to the advancement of science and technology, especially the application of exogenous hormones, tissue culture not only provides theoretically reliable experimental evidence for related disciplines, but also becomes a kind of a new method for large-scale, batch-scale production of seedlings.
The reason why plant tissue culture has developed so rapidly is that it has such a wide range of applications due to the following characteristics:
- Culture conditions can be artificially controlled.
The plant material used in tissue culture is completely grown under artificially supplied culture medium and microclimate environment. It is free from the adverse effects of four seasons, day and night changes and severe weather in nature, and the conditions are uniform, which is very beneficial to plant growth. It is convenient for stable annual production.
- Short growth cycle and high reproductive rate.
Due to artificially controlled culture conditions of plant tissue culture, it provides different culture conditions according to various requirements of parts of plants, so the growth is faster. In addition, the plants are also relatively small, often 20–30d for a cycle. Therefore, although plant tissue culture requires certain equipment and energy consumption, since plant materials can be produced in a geometrical order, the overall cost is low, and high-quality seedlings or virus-free seedlings of uniform specifications can be provided in time.
- Convenient management, which is conducive to factory production and automation control
Plant tissue culture is conducted under certain conditions of temperature, light, humidity, nutrition, hormones, etc. in a certain place and environment, which is highly conducive to high intensification and high-density factory production, and is also conducive to automatic control of production.
It is the development direction of future agricultural factory cultivation. Compared with pot cultivation and field cultivation, it saves a series of complicated labors such as cultivating and weeding, watering and fertilizing, and controlling pests and diseases, which can greatly save manpower, material resources and land needed for field planting.
Lifeasible offers a complete range of high-quality plant tissue culture products that facilitate the development of new plant traits and large-scale production, including Amino Acids, Antibiotics, Auxins etc.