Cytokinins

Definition

Cytokinins are a class of plant hormones that promote cell division, or cytokinesis, in plant roots and shoots. These hormones play a crucial role in various plant processes, such as growth, development, and responses to environmental stimuli, making them essential for plant health and adaptation.

5 Must Know Facts For Your Next Test

1. Cytokinins are primarily produced in the roots and are transported to other parts of the plant, influencing growth patterns.
2. They work in conjunction with auxins to regulate the balance between cell division and elongation, which is critical for overall plant structure.
3. Cytokinins can delay leaf senescence (aging), helping to keep leaves green longer by promoting nutrient mobilization.
4. These hormones are also involved in the regulation of shoot development and lateral bud growth, helping plants adapt to their environment.
5. Cytokinins can be synthesized artificially and used in agriculture to enhance crop yields and improve shelf life of fruits and vegetables.

Review Questions

• How do cytokinins interact with auxins to influence plant growth?
  • Cytokinins and auxins work together to control the balance between cell division and elongation in plants. While cytokinins promote cell division, auxins stimulate cell elongation. The interaction between these two hormones helps determine the overall architecture of the plant, influencing root and shoot growth patterns. This balance is crucial for healthy plant development and adaptation to environmental conditions.
• What roles do cytokinins play in delaying leaf senescence and how might this be beneficial for agricultural practices?
  • Cytokinins play a significant role in delaying leaf senescence by promoting nutrient mobilization within the leaf tissues. This action keeps leaves green for longer periods, allowing the plant to continue photosynthesis effectively. In agricultural practices, using cytokinins can enhance crop yields by prolonging the productive life of leaves and improving the quality of fruits and vegetables, as they remain fresh for an extended time.
• Evaluate the impact of cytokinins on shoot development and lateral bud growth in response to environmental changes.
  • Cytokinins significantly influence shoot development and lateral bud growth by promoting cell division in these areas. When environmental conditions change, such as increased light availability or competition for resources, cytokinins can stimulate the growth of lateral buds, allowing plants to adapt by branching out or growing taller. This ability to respond to their environment ensures that plants maximize their access to light and nutrients, showcasing the importance of cytokinins in survival and adaptation.

Related terms

Auxins:

A group of plant hormones that regulate various aspects of growth and development, including cell elongation, apical dominance, and fruit development.

Gibberellins: Plant hormones that promote stem elongation, seed germination, and flowering, playing a vital role in growth and developmental processes.

Abscisic Acid: A plant hormone involved in regulating water loss and stress responses, often acting as a growth inhibitor and promoting seed dormancy.