Plant Hormone Fill-in Notes
What are these compounds?
- Plant hormones : ____________________ , organic plant __________________ growth substances transported __________________ the plant in __________________ concentrations that regulate plant __________________ processes.
- Plant Growth Regulators (PGR) : __________________ or natural compounds that __________________ plant physiological processes such as __________________ and __________________ .
Growth Promoting Hormones
- Auxins : Stimulate cell __________________ and are used to stimulate initiation of __________________ __________________ on cuttings. Examples: Indole-3-acetic acid (IAA) Jmol
- Gibberellins : Stimulate cell __________________ also important in seed __________________ . Example: GA3 Jmol
- Cytokinins : Stimulate cell __________________ and are important in shoot __________________ and and branching.
- Brassinosteroids : Promote cell __________________ in __________________ .
- Ethylene : Stimulates swelling of roots and stems. Used to promote __________________ of fruit. Jmol
- Abscisic acid (ABA) : __________________ __________________ to promote survival. Jmol
A Note on Concentrations
Hormones are present in very minute concentrations. PGRs are also applied in very low concentrations. __________________ concentrations can act as __________________ (2,4-D)
- One part per million (1 ppm) is equivalent to 1 mg of material in 1 liter of solution
- 1% = 10,000 ppm
- 1 ppm ≈ 1 __________________ in 4 hot tubs (5ml in 5000l).
Reference: The Biology of Horticulture. Preece, John E. 2005. John Wiley & Sons.