Science Fridays V. 2

Science Fridays: The many roles of Auxin: A critical plant hormone

Unlike many mammalian hormones, plant hormones usually perform many separate functions in the plant body, this is especially true of Auxin.  Let’s look at three novel roles of Auxin.  Keep in mind there are many more.

1) Apical Dominance: The tallest point of the plant is called the apex and produces Auxin in abundance.  The Auxin moves down and laterally and keeps lower buds dormant: this phenomenon is called apical dominance.  Many growers will prune their plants back, temporarily halting apical dominance and allowing the plant to branch out and become more bushy. 

2) Phototropism: Have you ever placed a plant near a sunny window or light source and observed the plant slowly bending towards the light?  We call this phototropism, and is also regulated by Auxin.

3) Root Initiation: Auxin both promotes and inhibits root initiation; based on concentration.  In-fact most cloning gels and powders contain synthetic Auxin derivatives as an active ingredient. 

For more on Auxin see: