Plant hormone

From Wikipedia, the free encyclopedia

Plant hormones (or plant growth regulators, or PGRs) are internally-secreted chemicals in plants that are used for regulating the plants' growth. According to a standard definition, plant hormones are signal molecules produced at specific locations, that occur in very low concentrations, and cause altered processes in target cells at other locations.

Contents 1 Characteristics 2 Classes of plant hormones 3 See also 4 External links

[edit] Characteristics

• The concentration of hormones required for the plant response is very low (10^-6 to 10^-5 mol/L), compared to the requirement of minerals and vitamins for plants.
• The synthesis of plant hormones is more diffuse and not always localized.
• Action at a distance is not a must for a plant hormone. Also used in commercial cloning processes.

[edit] Classes of plant hormones

It is accepted that there are five major classes of plant hormones:

1. abscisic acid (ABA)
2. auxins
3. cytokinins(CKs)
4. ethylene
5. gibberellins (GAs)

[edit] See also

• Hormone
• Bacterial hormone

[edit] External links

• The Top Plant Hormone (Non-Theory) Site on The Web
• Another Good Site
• Sidwell Friends Plant Hormone Table - The Inspiration of the Plant Hormone Tables in Wikipedia and in the Article Above
• Hormonal Regulation of Gene Expression and Development - Detailed Intro Including Genetic Information