Cytokinins

Definition

Cytokinins are a class of plant hormones that promote cell division and growth. They play a crucial role in various plant processes, including shoot and root development, leaf expansion, and delaying senescence. These hormones influence the activity of other hormones and are essential in regulating the balance between growth and development in plants.

5 Must Know Facts For Your Next Test

1. Cytokinins are primarily synthesized in the roots of plants and then transported to other parts where they stimulate growth.
2. They work synergistically with auxins to promote balanced growth and development, particularly in the formation of new shoots.
3. Cytokinins delay leaf senescence by promoting cell division and maintaining chlorophyll levels, which enhances photosynthesis.
4. These hormones can be applied externally to plants to stimulate growth and improve yields, especially in agricultural practices.
5. The effects of cytokinins can vary based on their concentration and the presence of other hormones, highlighting their complex role in plant physiology.

Review Questions

• How do cytokinins interact with other plant hormones to influence growth?
  • Cytokinins interact closely with auxins to regulate plant growth and development. While cytokinins promote cell division and shoot formation, auxins encourage root development. The balance between these two hormones is vital; an excess of cytokinins can lead to excessive shoot growth at the expense of roots, while higher levels of auxins can suppress shoot formation. This intricate interplay ensures that plants maintain a healthy structure as they grow.
• Discuss the role of cytokinins in delaying leaf senescence and its implications for plant health.
  • Cytokinins play a significant role in delaying leaf senescence by promoting cell division and maintaining chlorophyll levels. By preventing the natural aging process in leaves, these hormones help sustain photosynthesis for longer periods, which can enhance overall plant health and productivity. This delay in senescence is particularly beneficial for crops, as it can lead to higher yields by allowing more time for nutrient accumulation before harvest.
• Evaluate the potential applications of cytokinins in agriculture and how they can impact crop production.
  • The application of cytokinins in agriculture has the potential to significantly improve crop production by stimulating growth and delaying senescence. By applying these hormones externally, farmers can enhance fruit set, increase yield, and improve the quality of produce. Additionally, cytokinins can help crops adapt better to environmental stressors like drought or nutrient deficiency. Evaluating the appropriate concentration and timing for application is crucial for maximizing these benefits while minimizing any adverse effects on plant health.

Related terms

Auxins: Auxins are another class of plant hormones that regulate various aspects of growth, such as elongation of cells, apical dominance, and root formation.

Gibberellins: Gibberellins are hormones that promote stem elongation, seed germination, and flowering in plants, working in conjunction with cytokinins to coordinate growth.

Abscisic Acid: Abscisic acid is a plant hormone that primarily acts as a growth inhibitor, helping plants respond to environmental stress by promoting seed dormancy and closing stomata.