Auxin inhibits the growth of lateral axillary buds.



Auxin is a plant hormone that plays a crucial role in regulating various aspects of plant growth and development. One of the effects of auxin is the inhibition of lateral axillary bud growth.



Auxin is primarily produced in the apical meristem, which is the growing tip of the plant. It is then transported downwards through the stem, where it exerts its effects on various plant tissues and organs. Auxin promotes cell elongation, regulates apical dominance, and controls the direction of plant growth.



Apical dominance refers to the phenomenon where the growth of the apical bud (located at the tip of the stem) is favored over the growth of lateral axillary buds (found in the leaf axils, at the base of leaves). This is important for maintaining the plant's vertical growth and preventing the excessive branching of the stem.



Auxin inhibits the growth of lateral axillary buds by suppressing their development and elongation. It does so by promoting the production of strigolactones, which are a class of plant hormones that inhibit lateral bud outgrowth. Strigolactones are synthesized in the root and transported upwards to the shoot, where they act as inhibitors of lateral bud growth.



The inhibition of lateral bud growth by auxin ensures that the plant's energy and resources are primarily directed towards the growth and development of the apical bud. This allows the plant to maintain its vertical growth and form a dominant main stem. It also prevents excessive branching, which can divert resources away from the main stem and reduce the plant's overall growth and productivity.



In conclusion, auxin inhibits the growth of lateral axillary buds by promoting the production of strigolactones, which act as inhibitors of lateral bud outgrowth. This mechanism ensures apical dominance and promotes the vertical growth of the plant.