Characteristics of Plant Growth Regulators
Plant growth regulators (PGRs) are small, simple molecules that exhibit diverse chemical compositions. These compounds play crucial roles in managing growth and developmental processes in plants. The major types of PGRs include auxins, gibberellins, cytokinins, abscisic acid, and ethylene, each exhibiting unique physiological effects.
Classification of PGRs
PGRs can be broadly categorized into two groups:
- Growth Promoters - These PGRs stimulate growth-related processes like cell division, flowering, and fruit formation. Examples include auxins and gibberellins.
- Growth Inhibitors - These compounds help plants respond to stress, assisting in dormancy and abscission. An example is abscisic acid, known for its role in stress responses.
Additionally, the discovery of major PGRs has been rooted in both experimental observations and accidental findings, highlighting their importance in plant biology. The distinct pathways through which these molecules influence plant physiology make them essential for agricultural practices and understanding plant life cycles.