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Plants have some impressive traits that humans don't have. They can reproduce asexually (i.e. clone themselves) and regenerate damaged parts throughout their lives. If a human loses a limb, they definitely can't grow it back!

All of this is possible because of the plant's stem cells or meristem. Stem cells are unspecialised cells that can differentiate (develop) into any new kind of tissue - leaves, stems, roots, flowers; you name it! Once humans are fully grown, they no longer have this type of stem cell. So, let's find out more about the meristem.

The Definition of the Meristem

The meristem is a specialised type of plant tissue that is made up of undifferentiated cells that are capable of dividing indefinitely. These meristematic cells are essentially stem cells that are clumped together and can develop into all other types of plant tissues and organs.

Learn more about Cell Differentiation and Stem Cells by checking out our articles!

Meristem tissues are regions of plant cells capable of division and growth.

Meristematic cells are undifferentiated cells, found in the meristem tissue, that can divide into similar cells or give rise to differentiated plant tissues and organs.

Stem cells are a type of cell from which all other specialised cells with specific functions are generated from.

Meristematic cells are totipotent stem cells. This is what makes them so unique.

Totipotent cells have the ability to self-renew and can develop into any specialised plant tissue.

Plant meristematic cells can divide and develop throughout the plant's entire lifespan. This enables plants to keep growing and repairing themselves until they die, unlike most animals.

A quick recap on cell division! Mitosis produces two identical daughter cells from a singular parent cell.

Most human cell division occurs via mitosis, except for the production of gametes.

  • A cell gets ready to divide. The chromosomes in the cell's nucleus replicate, thicken, and coil up.
  • The nuclear membrane disintegrates. The chromosomes line up in corresponding pairs in the middle of the cell.
  • The pairs are split up and pulled to opposite sides of the cell.
  • New nuclei are formed. The cytoplasm is split between the two cells, and they divide.

These new cells can be used for growth or repair.

To learn more about cell division and mitosis, check out our article on Mitosis and the Cell Cycle!

Types of Meristems

Meristem tissues are categorised according to their location in the plant. Apical meristems are found in the root and shoot tips. There are also lateral meristem tissues found in the middle of the plant. Typically, apical meristems support vertical growth, whilst lateral meristems support plant widening.

But it's worth noting that there are a couple of exceptions to this rule, such as grass!

Grass continues to grow even after it has been mowed and the apical meristem in the shoot has been cut off. This is because most of a grass plant's growth comes from its lateral meristem tissues. The blades of grass grow from the middle rather than the top.

Apical Meristems

Both root and shoot meristems are formed during development. The cells in this region elongate and divide to support the growth and development of new meristematic cells. These new cells will then differentiate into the required specialised cells.

Meristem apical meristems StudySmarterFig. 2: An example of the apical meristems - in the shoots and roots, unsplash.com

Radical Meristem

The radical meristem is a small region of stem cells at the tip of a root. These cells can divide and form new root tissue. An outer part of parenchyma cells, known as the root cap, protects the apical meristem inside the soil from external environmental stressors.

The radical meristem allows roots to grow longer, maximising access to water, nutrients, and minerals in the soil.

Shoot Meristem

Shoot meristems (also known as terminal buds) are found at the ends of all branches and stems. These areas can grow and develop indefinitely, possessing the ability to transform into leaves, branches, flowers and fruits. Shoot meristem tissue aids with reproduction and maximises access to sunlight for photosynthesis.

Lateral Meristems

Some meristem tissues are found in the middle of the plant, rather than at the ends.

An example is the cambium. This lateral meristem tissue is located between the xylem and the phloem in a plant stem. It allows the stem to grow wider and form woody tissue, strengthening the plant.

The Function of the Meristems

Meristematic tissue supports multiple functions within the plant.

Primary Growth

Cell elongation and division trigger primary growth.

Primary growth is the increase in a plant's height or root length.

How does this benefit the plant?

  • Increased height: the plant gets taller. This enables better access to sunlight for photosynthesis.

  • Increased root length: the plant has a greater ability to access water, minerals and nutrients in the soil.

Wound Repair

Meristem cells can form inside injured tissues, differentiating into new, undamaged cells to control wound healing.

Hormone Production

Three different types of plant hormones control the elongation and division of meristem cells. The hormones are summarised in this table.

HormoneFunction
GibberellinPromotes stem elongation
CytokininPromotes cell division
AuxinPromotes cell elongation

Gibberellin is not produced in the meristematic tissue, but cytokinin and auxin are.

Shoot and root tips are the production site of auxin, a significant plant hormone. Auxin stimulates cell elongation. This commonly happens in the 'darker' side of the plant stem that faces away from a light source. Longer cells in the darker side of the stem allow the plant to bend towards the light. Furthermore, auxin controls apical dominance. If the apex of the shoot (and, thus, the site of the apical meristem) is removed, auxin is no longer produced. This triggers the lateral meristems to start growing.

Cytokinins are another vital plant hormone produced in apical meristems. They promote cell division.

Producing Identical Plants

Meristem tissues can differentiate into any type of plant cell. As a result, these cells can be used to produce clones of entire plants. This method is a quick and cheap way to prevent the extinction of rare species. Additionally, this cloning method can be used to grow crops of identical plants with positive traits such as disease resistance or a high yield.

An Example of Using Meristem

Meristematic cells can be used to clone plants quickly and economically. How does it work?

Firstly, the meristematic cells are removed from a plant and grown in tissue culture.

Tissue culture is the growth of cells outside an organism.

The tissue culture is grown in a culture medium, which contains:

  • Agar: a jelly-like material derived from seaweed, used for support

  • Nutrients: for growth and repair

  • Plant hormones: to stimulate growth and cell division

It's much quicker to produce new plants by cloning than by collecting and sowing seeds.

Clones will be genetically identical to the original plant that provided the meristem cells. This is useful for the large-scale cultivation of crops with desirable traits, such as drought tolerance.

Additionally, cloning plants in tissue culture is an easy and effective way of producing new individuals, helping to preserve endangered plant species.

Meristem Tissue Facts

  • Meristem tissues are critical for human survival. Essentially, they hold the blueprint for the fuels we burn, the food we eat and the oxygen we breathe!

  • Cloning plants using their meristem tissue is a common propagation method. Meristem tissues have been used to clone potatoes, corn, sugarcane and bananas.

  • The cellular and molecular structure of meristem tissues are very similar across many different plant species.

  • Meristem tissues allow some trees to live for thousands of years.

The oldest tree in the world is a bristlecone pine in California. The Methuselah tree is named after a Biblical figure who lived for almost a millennium. The Methuselah Tree is nearly 5000 years old. In comparison, the world's oldest vertebrate is the Greenland Shark. They live for an average of 400 years.

  • Plant's meristem cells cannot be used in human healthcare. However, they possess antioxidant and anti-inflammatory properties, often used in skincare products.

Meristem - Key takeaways

  • Meristem tissues are regions of plant cells capable of division and growth. These cells are totipotent - meaning they can differentiate into any specialised cell type.

  • Apical meristems are found in a plant's shoots and roots, whilst intercalary and lateral meristems are located in the centre of the plant.

  • The hormones gibberellin and auxin control cell elongation, while cytokinins promote cell division.

  • The meristem tissue is used for primary growth, wound repair, hormone production and plant cloning.


1. CGP, GCSE AQA Combined Science Revision Guide, 2021

2. Edexcel, Salters-Nuffield A level Biology, 2015

3. Kara Rogers, Mitosis, Britannica, 2020

4. M.J. Farabee, Plant Hormones, Nutrition, and Transport, 2007

5. Melissa Petruzzello, Meristem, Britannica, 2020

6. National Geographic, Greenland Shark, 2022

7. Oregon State University, Mechanisms for Growth, 2022

8. Pratima Bajpai, Biermann’s Handbook of Pulp and Paper (Third Edition), 2018

9. Reinhard Renneberg, Biotechnology for Beginners (Second Edition), 2017

10. Robin McKie, The Methuselah tree and the secrets of Earth’s oldest organisms, The Guardian, 2020

11. Srishti Aggarwal, Plant stem cells and their applications: special emphasis on their marketed products, Biotech, 2020

12. Susan T. Rouse, Meristems, Encyclopedia.com, 2022

13. Thomas Greb, Plant Stem Cells, Current Biology, 2016

Frequently Asked Questions about Meristem

The meristem is a region of cells that are capable of division and growth.

The three types of meristems are apical, intercalary and lateral.

Meristematic tissues are regions of stem cells.

Without meristems, plants would not be able to grow or repair themselves.

Meristems allow primary growth, wound repair, hormone production and plant cloning.

Final Meristem Quiz

Question

What are meristem tissues?

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Answer

Meristem tissues are regions of plant cells capable of division and growth.

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Question

What makes totipotent cells special?

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Answer

Totipotent cells can develop into any kind of specialised plant tissue.

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Question

Which of these words best describes the term 'differentiate'?

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Answer

Develop

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Question

Where are apical meristems found?

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Answer

Apical meristems are found in the shoots and roots of plants.

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Question

Where are the lateral and intercalary meristems found?

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Answer

Lateral and intercalary meristems are found in the middle of the plant.

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Question

What protects the root meristem from the soil?

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Answer

A layer of parenchyma cells known as the cell cap protects the meristem from the soil.

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Question

Which hormone promotes cell division?

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Answer

Cytokinin

Show question

Question

What is primary growth?

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Answer

Primary growth is the increase in a plant's height or root length.

Show question

Question

Where are the plant hormones auxin and cytokinin produced?

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Answer

These hormones are produced in the meristematic tissue.

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Question

Which meristematic tissues generally support plant widening?

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Answer

Intercalary and lateral meristematic tissues

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Question

How do apical meristem cells support the growth and development of new cells?

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Answer

Apical meristem cells elongate, divide and differentiate.

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Question

Where is the cambium meristem tissue found?

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Answer

The cambium meristem tissue is found in between the xylem and the phloem.

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Question

Which plant hormone does not promote cell elongation?

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Answer

Cytokinin

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Question

Meristem cells can contribute to wound healing. True or false?

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Answer

True

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Question

What are some uses for plant cloning?

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Answer

Uses for plant cloning include protecting the extinction of rare species and growing crops with desirable traits.

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