Cytokinins

Definition

Cytokinins are a class of plant hormones that play a crucial role in regulating various aspects of plant growth and development, particularly cell division and differentiation. These hormones are produced in the roots and are transported to other parts of the plant, influencing processes such as shoot and root growth, leaf expansion, and delay of senescence. They are essential for maintaining a balance between growth and stress responses, highlighting their significance in plant-associated microbiomes and their impact on crop health.

5 Must Know Facts For Your Next Test

1. Cytokinins are involved in promoting cell division by activating specific genes responsible for this process.
2. These hormones help delay leaf senescence, which can improve crop yields by allowing plants to maintain their photosynthetic capacity longer.
3. Cytokinins interact with other plant hormones like auxins and gibberellins to fine-tune growth responses to environmental conditions.
4. They play a significant role in establishing symbiotic relationships with beneficial microbes in the soil, which can enhance nutrient uptake.
5. Research has shown that applying cytokinins can help crops tolerate environmental stresses such as drought and salinity.

Review Questions

• How do cytokinins interact with other plant hormones to regulate growth and development?
  • Cytokinins interact closely with auxins and gibberellins to coordinate various aspects of plant growth. While cytokinins promote cell division and shoot development, auxins encourage cell elongation and root formation. This interaction creates a balance that ensures healthy plant structure and function, enabling plants to respond appropriately to their environment.
• What is the role of cytokinins in delaying leaf senescence, and how does this affect crop yield?
  • Cytokinins delay leaf senescence by promoting continued cell division and photosynthetic activity in leaves. This results in prolonged nutrient production, which can significantly enhance overall crop yield. By delaying aging processes in leaves, plants can better support fruit and seed development, leading to higher productivity.
• Evaluate the potential benefits of applying synthetic cytokinins in agricultural practices, particularly regarding stress tolerance in crops.
  • Applying synthetic cytokinins can greatly benefit agricultural practices by enhancing stress tolerance in crops under challenging environmental conditions. By improving root development and promoting resilience against factors like drought and salinity, these hormones can lead to better water use efficiency and nutrient uptake. This not only helps maintain crop health during adverse conditions but also contributes to sustainable agriculture by reducing reliance on chemical fertilizers and irrigation.

Related terms

Auxins:

Auxins are another class of plant hormones that primarily regulate cell elongation and play a role in the growth direction of plants.

Gibberellins: Gibberellins are hormones that promote stem elongation, seed germination, and flowering in plants, often working alongside cytokinins.

Ethylene: Ethylene is a plant hormone involved in regulating fruit ripening, flower wilting, and leaf fall, and it can interact with cytokinins to influence plant responses.