Brassinosteroid
Encyclopedia : B : BR : BRA : Brassinosteroid
Brassinolid appears to be the most common Brassinosteroid.
Brassinosteroids (BAs) are a group of plant hormones.
Location, Characteristics and Occasions for Synthesis Induction
- Released in mature cells (and less so in immature cells) when they have less than enough sugar and oxygen to support both themselves and any dependent cells ([speculative])
- Released in response to root environmental, pest, or disease stress
- The most common form of brassinosteroids is brassinolide.
- May work in concert with Gibberellin or be part of the hormone effect cascade ([speculative])
- Is visually similar to the animal hormone cortisol and may function in a similar manner, raising phloem sugar levels to deal with short term environmental stress just like cortisone.([speculative])
Effects
- Increased rate of stem elongation
- Leaf senescence inhibition
- Involved in gravitropism
- Bending of grass leaves at the sheath/blade joints
- Inhibits leaf abscission
- Inhibits root growth
- Resistance to stress (Interpretation: this occurs just in the shoot. It's done by rerouting resources from the root to the stressed shoot) ([the parenthetical is speculative])
- Stimulates cell elongation and division. (Maybe just in the shoot) ([the parenthetical is speculative])
- Enhanced Ethylene production. (Interpretation: induced indirectly by the causation of root cell senescence) ([the parenthetical is speculative])
- Increased auxin response ([Bao et al., 2004])
- Promotion of growth. (Maybe just shoot growth) ([the parenthetical is speculative])
- Xylem differentiation promotion. (Interpretation: in order to transfer resources from cannibalized root cells) ([the parenthetical is speculative])
- Inhibits the rate of metabolism of cells in the root (Perhaps to funnel resources to the shoot) ([the parenthetical is speculative])
- Acts as an indicator of poor shoot efficiency and low sugar and gases. Thus all its effects, such as inhibiting root growth, possibly inhibiting root metabolism, possibly releasing stored sugars and gases and promoting shoot growth may be an attempt to increase sugar and essential gases. For example at night when little light is available to make sugar, there may be high levels of BA. ([speculative])
| Plant hormones | [edit] |
| Abscisic acid - Auxins - Cytokinins - Ethylene (Ethene) - Gibberellins |
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.