Back to: Botany 200 Level
Hello, brilliant learner! Have you ever wondered how plants grow new shoots, leaves, and branches? Or how some plants stay fresh for longer after being harvested? The secret lies in a powerful plant hormone called cytokinins!
Today, we’ll learn how cytokinins help plants by promoting cell division and shoot development. Let’s get started!
Cytokinins and their function in cell division and shoot development
What Are Cytokinins?
Cytokinins are plant hormones that stimulate cell division (cytokinesis) and promote the growth of shoots, leaves, and buds. They work together with auxins to maintain a balance between shoot and root growth.
Cytokinins are mainly produced in the roots but travel through the plant to help in:
✅ Cell division (mitosis), which is essential for growth.
✅ Formation of new shoots, branches, and leaves.
✅ Delaying ageing (senescence) in leaves and fruits.
Let’s break these roles down.
1. Cytokinins and Cell Division
Cell division is the foundation of plant growth. Without it, plants wouldn’t be able to increase in size or develop new tissues. Cytokinins are key players in stimulating cell division in the meristems (regions where plant cells actively grow).
How Do Cytokinins Promote Cell Division?
Cytokinins activate special proteins called cyclins, which help cells divide.
They stimulate DNA replication, preparing cells for mitosis.
They ensure that newly formed cells differentiate into specialised plant tissues.
✅ Example: When a plant is cut or injured, cytokinins stimulate cell division to heal the wound and generate new tissues.
2. Cytokinins and Shoot Development
Cytokinins encourage the growth of shoots, leaves, and buds by promoting cell division and elongation.
How Do Cytokinins Help in Shoot Growth?
They stimulate the growth of shoot buds, leading to more branches and leaves.
They prevent apical dominance, allowing side branches to grow.
They work opposite to auxins, ensuring a balance between root and shoot development.
✅ Example: In plant tissue culture (cloning), scientists use a high cytokinin-to-auxin ratio to develop new shoots and leaves from plant cells.
Other Functions of Cytokinins
✔ Delaying Ageing (Senescence): Cytokinins slow down leaf yellowing, keeping leaves and fruits fresh for longer.
✔ Breaking Seed Dormancy: Some seeds need cytokinins to wake up and start growing.
✔ Enhancing Nutrient Flow: Cytokinins attract nutrients to where they are most needed in the plant.
Why Are Cytokinins Important?
✅ Help plants grow new shoots, branches, and leaves.
✅ Stimulate cell division, leading to plant growth.
✅ Prevent ageing in leaves and fruits, keeping them fresh.
✅ Used in agriculture and plant cloning to improve crop production.
Summary
Cytokinins stimulate cell division, which is essential for plant growth.
They promote shoot development by helping new branches and leaves grow.
They work with auxins to balance shoot and root growth.
Cytokinins delay ageing, keeping plants and fruits fresh for longer.
Farmers and scientists use cytokinins in plant tissue culture and crop improvement.
Let’s Test Your Understanding:
- What is the main function of cytokinins in plant growth?
- How do cytokinins help plants develop new shoots?
- Why do farmers use cytokinins in agriculture?
You’re doing an amazing job, superstar! Now you know how cytokinins help plants grow and stay fresh. Keep learning, and see you in the next lesson!
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