The absorption of light is made possible thanks to pigments , the most famous is certainly there but also chlorophyll and carotenoids , which unlike the first , absorb much green but not yellow or orange, from where their color and their name taken from the carrot that contains many . These pigments have two main roles : a role of light harvesting has been said , they transfer energy to chlorophyll , but also a photoprotective role they evacuate excess light energy , thereby preserving the process of photosynthesis.

What then is the mechanism at work that drives the plant to protect itself when the sunshine watching ? This is the question that three researchers , two of CRAG , Center for Research in Agrogenomique [ 1] Barcelona and the University of Texas , responded . Their explanation unveiled in the journal PNAS [ 2] is based on a specific protein , the PIF1 . From this work , it binds to the gene promoter PSY which is then suppressed until PIF1 degradation under the effect of excessive light, ” derepresses ” , which will then generate carotenoids. In other words , this beneficial protein binds to DNA near the gene PSY : well located, PIF1 gene ‘s protective pigment production but its degradation PSY gene reactivates and causes excess production of beneficial carotenoids.

[ 1] Website of CRAG weg : http://www.cragenomica.es/index.php
- [2 ] Article: “Direct regulation of phytoene synthase gene expression and carotenoids biosynthesis by phytochrome -interacting factors ” , by Gabriela Toledo- Ortiz , Enamul Huq and Manuel Rodriguez – Concepcion , published in PNAS June 7, 2010 , doi: 10.1073 / pnas.0914428107

Source:

- reference [2 ] in the text
- press release of June 10, 2010 CSIC