What is meant by apical dominance?
Apical dominance means that the growing apex of a plant controls the quiescence of buds sitting in lower positions along a shoot. In plants with strong apical dominance, the growth is very upright, with one dominant central axis, as for example in firs.
How do I break my apical dominance?
Apical dominance can be interrupted by increasing the ratio of cytokinin to auxin with a foliar application of the synthetic cytokinin in Configure. This reduces auxin’s ability to prevent axillary bud break and allows the axillary buds to escape from apical dominance.
How does auxin maintain apical dominance?
Auxins promote stem elongation, inhibit growth of lateral buds (maintains apical dominance). They are produced in the stem, buds, and root tips. This produces a curving of the plant stem tip toward the light, a plant movement known as phototropism. Auxin also plays a role in maintaining apical dominance.
How does cytokinesis control apical dominance?
Presence of cytokinin in an area causes preferential movement of nutrients towards it. When applied to lateral buds, they help in their growth despite the presence of apical bud. They thus act antagonistically to auxin which promotes apical dominance. Therefore cytokinin can overcome apical dominance, caused by auxins.
What is apical dominance Class 12?
Apical dominance is a phenomenon in which central stem is dominant and growth of lateral buds is inhibited. It is due to plant hormones produced in the tip of the shoot. Auxin hormone is responsible for apical dominance and cytokinin hormone is responsible for breaking the apical dominance.
What are auxins and cytokinins?
auxin: a class of plant growth hormones that is responsible for elongation in phototropism and gravitropism and for other growth processes in the plant life cycle. cytokinin: any of a class of plant hormones involved in cell growth and division.
What hormone promotes apical dominance?
hormone auxin
It is commonly accepted that the plant hormone auxin mediates apical dominance.
What can inhibit apical dominance?
Some fruit trees have strong apical dominance, and young trees can become “leggy”, with poor side limb development. Apical dominance can be reduced in this case, or in cases where limbs are broken off by accident, by cutting off the auxin flow above side buds that one wishes to stimulate.
What does auxin do to axillary buds?
Auxin keeps the dormancy of the axillary buds, but cytokinin releases and promotes the axillary meristem development.
How does auxin help in phototropism?
Auxins also play a part in phototropism, an occurrence that involves plants bending or moving away from light. The extra auxin present on the shaded side promotes more cell division and elongation, causing the plant to bend towards the sunlight after this lop-sided growth.
How does auxin inhibit lateral growth?
The apical bud produces a plant hormone, auxin, (IAA) that inhibits growth of the lateral buds further down on the stem towards the axillary bud. When the apical bud is removed, the lowered IAA concentration allows the lateral buds to grow and produce new shoots, which compete to become the lead growth.
Does cytokinin promote apical dominance?
Apical dominance is suppressed under the effect of high cytokinin concentration and permits the development of axillary buds.