|
Descripción
|
|
|---|---|
| Roots normally grow in darkness, but they may be exposed to light under certain circumstances. After perceiving light, roots reduce their growth and change direction to escape from light (negative phototropism). Root growth and tropic responses are sustained by cell proliferation in meristems followed by cell differentiation, which is controlled by different hormonal pathways and reactive oxygen species (ROS). Using light as a growth-conditional cue, we show that flavonols regulates light tropic response, root zonation and growth through repression of cell proliferation and promotion of cell differentiation. Flavonol levels are low when roots grow in darkness, but they strongly increase upon illumination. Unilateral illumination of roots induces accumulation of flavonols at the meristem side closer to light, promoting local cell differentiation and growth re-orientation away from light. In the root tip, flavonols repress proliferation through reduction of auxin signaling, the PLETHORA gradient, and superoxide radical content. In addition, flavonols inhibit accumulation of superoxide radical upon auxin activation. Genetic and chemical analyses show that flavonol accumulation is triggered in the root transition zone by pathways promoting differentiation (cytokinin and hydrogen peroxide). Flavonols, therefore, function as positional signals, integrating hormonal and ROS pathways to regulate negative light tropism and organ growth. | |
|
Internacional
|
No |
|
ISSN o ISBN
|
00000000 |
|
Entidad relacionada
|
CRAG, BARCELONA |
|
Nacionalidad Entidad
|
ESPAÑA |
|
Lugar del congreso
|
BARCELONA, Spain 24/10/2015 |