Lateral root

[3] Such control can be particularly useful, as increased auxin levels help to promote lateral root development, in young leaf primordia.

The cells in this part of the root have been seen to play a critical role in gravitropic response and releasing secretions to mobilize nutrients.

If sufficient signaling is present, pre-branching sites are developed in basal portions of meristematic tissue that are stable in the presence of high auxin environments.

These pre-branching sites go on to form the pericycle founder cells after they are stable and have high auxin accumulations.

In some cases, the activation of auxin biosynthesis takes place in these founder cells to reach a stable threshold.

[2] Signaling is important for the overall development and growth of a plant, including the production of lateral roots.

[5] A specific auxin transport inhibitor, N-1-naphthylphthalamic acid (NPA) causes indoleacetic acid (IAA) accumulation in the root apical meristem, while simultaneously decreasing IAA in radical tissue required for lateral root growth.

From this study, the following was concluded: Auxin is responsible for generating concentration gradients to allow for proper plant development.

Also, two auxin transporters that allowed for the hormone to exit cells, PIN-FORMEDs (PINs) were established, as well as ATP-binding cassette Bs (ABCBs)/P-glycoproteins (PGPs).

[1] PIN proteins recirculate the auxin upwards to the plant shoots for direct access to the zone of elongation.

When further investigated, it was discovered that the pin8 mutant was significant only as the lateral root was beginning to appear in the plant, suggesting that a function PIN8 protein is responsible for this action.