Cytokininer

Cytokinins are a class of plant hormones that play a crucial role in plant growth and development. They are primarily synthesized in the root tips and are transported upwards throughout the plant. Cytokinins are involved in a wide range of physiological processes, including cell division, cell differentiation, and the inhibition of senescence (aging).

One of the key functions of cytokinins is to promote cell division and stimulate the formation of new tissues. They work in conjunction with another plant hormone, auxin, to regulate these processes. The ratio of auxin to cytokinin is particularly important in determining the developmental fate of plant cells, influencing whether they develop into roots, shoots, or undifferentiated callus tissue.

Cytokinins also play a significant role in delaying the aging of plant leaves and other organs. They can prevent the breakdown of chlorophyll and other essential molecules, thus extending the functional lifespan of plant parts. This senescence-inhibiting effect is vital for maintaining photosynthetic activity and overall plant health. Furthermore, cytokinins are involved in nutrient mobilization, helping to transport nutrients to areas of active growth and development. Their influence extends to processes like bud formation and the regulation of stomatal opening and closing, impacting gas exchange and water balance.