She conducted extensive research into interactions between ethylene and auxin (another key plant hormone) in controlling numerous aspects of plant development.
Cytokinins act in concert with auxin, another plant growth hormone.
When cultured with auxin but no cytokinin, they grow large but do not divide.
It was first discovered that the plant hormone auxin likely regulates apical dominance in 1934.
However, its effect is much weaker than the effect of the basic auxin molecule indole-3-acetic acid.
These observations suggest that auxin signalling is essential in both syncytium and giant cell formation and implies a change in the local auxin balance upon nematode infection.
He proved the existence in plants of a transportable compound (baptized auxin and later shown to be indole-3-acetic acid) that was responsible for the regulation of elongation growth.
Auxin\kinetin ratio was also found to be important in triggering the surface changes, especially at high concentrations.
