Short- portion of the solar spectrum , especially blue light (390500 nm) and near ultraviolet (320390 nm) have a significant impact on the growth and development of plants . Research in the field of genetics and molecular biology , carried out mainly on the model plant Arabidopsis thaliana , allowed to know the three classes of receptors of blue light and UV- A fototropin , cryptochromes and flavoproteins with family Zeitlupe . Fototropiny ( phot1 and PHOT2 ) are serine / threonine protein kinases activated by light , intermediate reactions fototropicznych , migration, chloroplast , stomatal opening and short-term growth inhibition wydłużeniowego momentum . Cryptochromes ( Cry1 , Cry2A and Cry3 ) are photoreceptors containing FAD and pterin intermediate in the regulation of growth momentum, the development leaves photoperiodic induction of flowering and setting of the biological clock . ZTL , Fkf1 and Lkp2 are flawoproteinami forming a new family of blue light receptors that combines the presence of PAS domains / FMN binding LOV , cassettes F and six repeated theme KELCH . Recent studies suggest that flawoproteiny family ZTL function in the setting of the biological clock by participating in regulated by light degrading the protein component of the oscillator phone.