IAA (Indole-3-Acetic Acid) is the abundant and well known plant hormone of the auxin class. IAA is predominantly produced in the apical bud of and young leaves of plants and is known to be an inducer of cell division and elongation. IAA, as well as most other auxins, are also known to act in concert with, or in opposition to, other plant hormones. For example, the ratio of auxin to cytokinin in certain plant tissues determines initiation of root versus shoot buds.

IBA (Indole-3-butyric acid) is a plant hormone belonging to the auxin family and assists in initiating root formation; the in vitro process is called micropropagation. Aside from accelerating root formation, it is used on various crops to stimulate flower development and the growth of fruits. This ultimately increases crop yields.

Historically, products that contained IBA were used to protect plants during transplantation by stimulating root growth and decreasing shock.

Picloram is a synthetic auxin that is often used in the control of woody plants and broadleaf plants. Auxins typically act in concert with, or in opposition to, other plant hormones. For example, the ratio of auxin to cytokinin in certain plant tissues determines initiation of root versus shoot buds.

The plant hormones cytokinins (CKs) comprise a class of growth regulators involved in the stress response, senescence, photosynthesis, nutrient assimilation and mobilization, as well as modulation of a plant tissue’s ability to act as a sink or source of metabolites.

CKs are recognized by a subset of sensor histidine kinases (HKs) and the signal is transmitted to the nucleus via a multistep phosphorelay (MSP), thus activating the expression of target genes.