In this publication we shed light on the concept of plant tissue culture, the techniques employed, the main benefits, and the ways to enhance the process through automation.
Plant tissue culture involves a set of techniques with multiple applications, and it is currently a booming activity. This activity is carried out in specialized laboratories, whose professionals are dedicated to cultivate explants in vitro, that is, a separate part of a plant such as protoplasts, cells, tissues or organs, under strictly controlled environmental conditions with the purpose of producing large quantities of plants with the same genotype.
From a biological point of view, plant tissue culture is possible thanks to the cellular totipotentiality of meristematic tissues of plants, which are present in several organs. This attribute allows these plant cells to reproduce asexually and reverse their cellular differentiation and then differentiate again to form a new plant.
Plant tissue culture applies the knowledge of plant biotechnology, which covers different areas of life science as diverse as biochemistry, molecular biology, immunology, virology, food industry, pharmaceutical industry, genetics and agriculture.
The main applications of plant tissue culture
Plant tissue culture allows the study and genetic modification of plants in order to improve their resistance to viruses and insects, their nutritional value, their physical appearance or their metabolism. It also allows a greater understanding of the genetic and physiological processes of plants, since the environmental conditions of in vitro culture can be controlled and analyzed in-depth. It is the main approach used to develop the totipotency potential of plants and induce genotypic and phenotypic manipulation in plant cells.
Nowadays, plant tissue culture is an important tool, both in basic research and commercial applications. For example, biotech companies are continually innovating to develop better seeds that can yield more fruits per plant. In the cosmetics sector, collagen protein extracts or growth factors are produced from plant stem cells, avoiding the use of animals or animal tissues. In medicine, many pharmaceutical products and vaccines are obtained from genetically modified plants. However, the horticulture sector is witnessing a profound impact, as a significant number of companies are implementing vertical production of vegetables and fruits in greenhouses through the means of plant tissue culture. This approach offers several advantages, including the ability to cultivate plants with an identical genotype, higher productivity per unit of land, and increased resistance to pests.
Types of plant tissue culture
As we mentioned at the beginning of this publication, the term plant tissue culture covers multiple techniques, which, depending on their purpose and type of tissue ussed, can be distinguished into different types:
In this method, plant meristematic tissues are cultured under artificial conditions. It is ideal in cases of disease prevention caused by viruses, since these tissues are not usually affected by plant pathogens.
This technique initially utilizes a vegetative organ of a plant, such as a leaf, root, or stem. This method is used to preserve the structure and functions of the desired plant.
A callus is a mass of undifferentiated cells. This technique uses cells from a callus taken from any part of the plant, and then these cells are differentiated.
In this case, seeds are used for plant regeneration in an artificial environment.
In this method, cells are collected from a plant, protoplasts are obtained and then cultured for cell wall development, followed by tissue differentiation and growth of an adult plant.
It consists of the sterile isolation and in vitro growth of an immature or mature embryo with the objective of obtaining a viable plant.
Advantages and disadvantages of plant tissue culture over traditional techniques
Plant tissue culture has many advantages over traditional methods, and the following comparison table summarizes the main advantages of this set of techniques.
Standard procedure for plant tissue culture
We will not go into details about the different steps that constitute this technique because the laboratories dedicated to this task already know what it consists of. In addition, there are multiple varieties of plant tissue culture with different particularities. However, we believe it is appropriate to mention the main phases and then emphasize some of them. Generally, in vitro plant tissue culture consists of 5 stages:
Preparation of culture media
Tissue or explant development
Conditioning and acclimatization
Most of these steps are performed manually by qualified personnel and their duration fluctuates depending on the type of application used. Although a common denominator in all cases is the way of preparing culture media, which can be particularly tedious and manual. There are three ways of dealing with this procedure: procurement of finished product by purchasing it from an external supplier, manual preparation using an autoclave or automatic preparation using a media preparator.
Preparation of culture media used in plant tissue culture
Culture media used in plant tissue culture usually contain inorganic salts, growth regulators, vitamins, amino acids, carbohydrates and sometimes a gelling agent, although this is not a mandatory element. Other compounds such as antioxidants, growth retardants or natural organic complexes can also be added.
The pH of culture media must also be taken into account, because it affects both plant growth and the activity of growth regulators. Generally, pH should be adjusted to values around 5.5. In addition, culture media must be sterilized to avoid contamination with other microorganisms, and the most popular technique is moist heat sterilization using a laboratory autoclave.
As we already know, the correct preparation of culture media requires precision and control. It is necessary to add different components, ensure the accuracy of quantities and keep an exhaustive record of the provided amounts of each nutrient. The entire preparation is then sterilized at the desired temperature and duration, making the mixture homogeneous and ready to be dispensed into the corresponding glass or polypropylene containers under a laminar flow hood. The success of our work depends on all this. Accuracy and control can be difficult to achieve, considering that this task is carried out manually. Moreover, it is imperative to pay specific attention to the potential risk of contamination at every stage of the process.
We are confident in the professionalism of the personnel at your plant tissue culture laboratory. We are quite sure about their dedication and expertise. However, it must be acknowledged that there is always the possibility of human error. This potential risk should not be disregarded, as it could result in significant consequences, particularly with regards to the well-being and safety of our personnel. As well as regarding the quality of the prepared product and also a considerable loss of time, stamina and money.
The manual culture of plant tissue involves certain hazards, for the outcome of that process as well as for the personnel that handle those fluids. Below, we explain the reasons for this.
The risks of manually preparing culture media used in plant tissue culture
As we have already mentioned, in plant tissue culture there are three aspects that you should try to prevent:
All three aspects can represent a serious problem for your preparations, your laboratory and your employees. To overcome these issues, the solution lies in the automation of plant tissue culture. Automating the process to its fullest extent can save you from making mistakes during preparation and potential accidents, while saving both time and money.
We will review the different difficulties that may arise during a manual procedure, which can be solved by using an automatic equipment suitable for this purpose.
In culture media sterilization, one of the major obstacles is related to heat exposure, which can vary among samples, since the sterilization temperature, in most cases, is only monitored in a reference vessel or simply just for the chamber temperature. Also, during this process, the bottles with agar medium cannot be shaked, preventing the liquid from mixing uniformly.
Once the sterilization process is finished, the medium must be cooled down until it reaches its dispensing temperature, which requires a long waiting time to prevent the operator from getting burned when handling the containers. Additionally, if it is excessively cooled, the agar will gelify, and if it was prepared for subsequent dispensing, this will pose a significant challenge.
Inaccuracy is another characteristic related to the manual preparation of culture media, particularly in the preparation and dispensing steps. It can cause problems of homogeneity and composition, out-of-specification batches and variations in dispensed volumes. To solve this issue, any reputable laboratory should have a quality assurance system in place to ensure the quality of the production process. This system is often manual and laborious to report on a daily basis as it involves recording a lot of data derived from periodic controls.
Another major problem regarding plant tissue culture is related to potential accidents and, consequently, sick leave. Certainly, due to the nature of the work, you may have noticed that your staff performs repetitive tasks and is required to adopt uncomfortable postures that can lead to work-related illnesses, such as chronic lower back pain, joint pain, or other conditions over time. Likewise, the handling of objects at high temperatures can lead to burns and/or serious and dangerous irritations, despite the technical training provided to your operators, the established protocols and the required clothing and equipment.
Enhance the quality, increase your productivity, save labor, eliminate human error, and minimize occupational hazards with the RAYPA media preparator.
With our media preparator:
Finally, it is worth mentioning the ergonomic design of RAYPA’s AE-MP media sterilizer and its various safety devices, which prevent uncomfortable postures during long hours, irritations and injuries, thus avoiding accidents and work-related injuries. At RAYPA we prioritize, first and foremost, prevention and safety of the end user, therefore, our media preparators are equipped with the following safety features:
Automating processes involves managing and improving control over the entire cycle by tracking performance indicators to obtain a more reliable control and analysis. This guarantees homogeneous and higher quality samples with a lower risk of medium contamination and an increase in productivity with a significant reduction in costs.
In order to better manage this procedure, the media preparator records the entire process, step-by-step. Also, thanks to its large capacity, we can scale up and increase production if necessary, producing bigger volumes in less time. Therefore, the process is faster, and the laboratory is more efficient.
Please contact us if you would like to know more details about our AE-MP series culture media sterilizer, fully capable of preparing, sterilizing, cooling and dispensing your culture media in a single unit and with an excellent batch-to-batch reproducibility. We will be glad to attend you.