auksiinien

Auksiinien, also known as auxins, are a group of plant hormones that play a crucial role in various aspects of plant growth and development. They are primarily synthesized in the young leaves and developing fruits of a plant. The most well-known and abundant natural auxin is indole-3-acetic acid (IAA).

Auksiinien are involved in a wide range of physiological processes, including cell elongation, which is fundamental to stem and root growth. They promote phototropism, the bending of a plant towards a light source, by accumulating on the shaded side of a stem, stimulating cell division and elongation there. Similarly, auxins contribute to gravitropism, enabling roots to grow downwards and shoots to grow upwards in response to gravity.

These hormones also influence apical dominance, where the terminal bud grows more vigorously than lateral buds, suppressing their development. Auksiinien are important in fruit development and can be used commercially to stimulate fruit set and prevent premature fruit drop. Their synthetic analogs are widely used in agriculture and horticulture as herbicides, plant growth regulators, and in rooting powders to encourage the formation of new roots on cuttings. The concentration of auxins within plant tissues is tightly regulated, ensuring precise control over developmental processes.