2 major nutrient components of culture media
Isn’t it captivating to see how nature and science works hand in hand to form a complete plant using merely some tissues?
Over the last few decades, tissue culture has transformed the way most industries produce plants. But we know very little about what plants actually need to grow in laboratory conditions.
There have been extensive studies already done on plants to determine what nutrients are essential for a particular plant to grow healthy and nutritious. The same studies have been further used to determine the major nutrients required for the development of a healthy plant using tissue culture.
So here we will start talking about the important components of culture media which we should provide for proper growth and development of plants. Generally, in field conditions, farmers supply only few commonly available inorganic elements (such as: Nitrogen, Phosphorus and Potassium) in different combinations and we call them fertilizers.
However, we need to provide more elements which a plant in field conditions would otherwise get from soil and water. There are several inorganic and organic chemical reactions happening in the soil which produce the necessary elements for the plants to uptake. In tissue culture, all these elements are provided in the culture media in limited quantities.
Interestingly, there are several tissue culture companies around the world, which offer services to prepare tissue culture protocols for specific plants and even for specific varieties. One of the major parts of preparing a protocol for them is to prepare the best tissue culture media recipes which enhances the success rate to as maximum as possible.
There is a growing demand globally for such a service as different industries require uniform plants in large numbers. This branch in tissue culture industry has been generating good revenues. If you want to know more about how plant tissue culture can help you generate large profits, then do consider checking our article on "8 ways plant tissue culture generates profit".
By now you might get an idea that success of tissue culture largely depends on culture media recipes and the composition of different nutrients in it. It is also important to know and understand the functions of each element and why we should consider supplying them for tissue culture.
We will discuss in this blog post 2 major classes of inorganic nutrients which we use in tissue culture media and certain important information regarding them:
Here the key thing to know is that macronutrients are elements which we need in large quantities (millimolar) for plants to have good growth and development. The major macronutrients used here are Nitrogen, Potassium, Phosphorus, Calcium, Magnesium and Sulphur.
N: Among these, Nitrogen plays the most vital role! It is crucial for growth of a plant in tissue culture as it is an important component for amino acids, nucleic acid and proteins.
P: Phosphorus is crucial for cell division and also to store energy in plant cells.
K: Potassium is necessary for normal cell division and promotes meristematic growth. Meristematic cells are cells that divide actively throughout life and develop into different organs.
Ca: Calcium is an integral part of plant cell walls and helps forming bonds to keep the cells intact and together. It also helps in regulation of hormone responses and promotes root development. While following different steps of tissue culture for certain plant species, you will notice that initiating roots and developing healthy roots can be a challenging task.
Mg: Magnesium is an important component of chlorophyll molecules. Chlorophyll helps plants to absorb energy from light and help them provide food for growth.
S: Sulphur is crucial for proteins, promotes root development and deep green foliage.
Plants are quite sensitive systems, so you should always be careful with the amount of nutrients you supply to them. If you provide too much of any element, tissue cultures will show poor growth or might just die.
Micronutrients, as the name suggests, are the critical elements that you need for good growth but in extremely small quantities. These include Boron, Manganese, Iron, Zinc, Copper, Molybdenum, Cobalt and Iodine.
B: Boron is important for movement of sugar, water and hormones. It also plays a role in nitrogen metabolism in plants, fruiting and cell division.
Cl: Chlorine helps in stimulating photosynthesis and is necessary for growth.
Cu: Copper helps in energy conversions for plants to use. This element also helps in chlorophyll synthesis.
Fe: Iron is the most important microelement which plants need. Plants use it for chlorophyll synthesis and also for conversion of energy happening during photosynthesis. It also supports the process by which carbon dioxide and water, using light and chlorophyll, prepares energy and releases oxygen. However, in layman terms, it is used to bond with other elements (called as 'chelation') so that it is more readily available for the tissues in culture media.
Mo: Plants use Molybdenum for normal growth and protein synthesis.
Zn: Plants use Zinc for activating enzymes in the process of chlorophyll formation.
I: Iodine can sometimes become handy in trace amounts. It is not an essential element. However, for tissue culture media of certain plants we need it in order to have proper protein synthesis.
Co: Cobalt is present in the vitamin B12 molecules. It is essential for fixation of nitrogen. In soil it helps in the conversion of atmospheric nitrogen to a form (nitrates) which is readily available for plants to use. This conversion is done by using nitrogen fixing bacteria.
All these elements are crucial in tissue culture and they follow the theory of limiting factors. It just means that if any of the required element is missing in the growth medium, then all the other elements present are of little or no value.
We hope this article will be useful for everyone who is interested in plant tissue culture. There will me more articles on different aspects of culture media in coming weeks. Keep checking this space!
By Nancy Bhatia | 28-April-2021
- Kyte, Kleyn, et al (2013) Plants from test tubes: An introduction to micropropagation. Timber press, Inc.
- Bhojwani, S.S., & Dantu, P.K. (2013). Plant Tissue Culture: An Introductory Text. Springer India
- Robert H. Smith (2013). Plant Tissue Culture- Techniques and Experiments. Elsevier Inc.
- Chapter 3 Tissue culture media (1996). Retrieved April 28, 2021, from https://www.sciencedirect.com/science/article/pii/S092834209680005X
- The_Components_of_Plant_Tissue_Culture_Media_I_Macro-_and_Micro-Nutrients. (n.d.). Retrieved April 28, 2021, from https://www.researchgate.net/publication/226836015_The_Components_of_Plant_Tissue_Culture_Media_I_Macro-_and_Micro-Nutrients