IN a recent paper, Galston 1 has shown that βindoleacetic acid, at concentrations of 1–10 p.p.m., inhibits the growth in the dark of excised stem tips of Asparagus, in contrast to its normal ...

A study at the University of Cordoba shows how algae produce auxin, a plant hormone, opening a path of communication with ...

Auxin is one of the major five plant hormones, mostly present natively as free or conjugated indole-acetic acid (IAA), a tryptophan ... such as shoot and root growth, development, cell expansion ...

This is just like phototropism, in that auxin in the root inhibits growth and auxin in the stem promotes growth.

Auxins are chemicals that control the growth of plants by promoting cell division and causing elongation in plant cells (the cells get longer).