Question
Pruning of plants promotes branching because the axillary buds get sensitized to
ethylene
gibberellin
cytokinin
indole acetic acid.
Solution
D.
indole acetic acid.
“It has been known since the 1930s that the plant hormone auxin is released by the plant’s actively growing tip and is transported down the main stem where it has an indirect effect on buds to inhibit branching. There are a number of ways in which the hormone exerts this effect and we have discovered a new path by which it works.”
The research suggests that for a shoot tip to be active, it must be able to export auxin into the main stem. But if substantial amounts of auxin already exist in the main stem, export from an additional shoot tip cannot be established
