Growth and development of plant occur under great influence of light, that quality and quantity changes are received by the specific photoreceptors. Various photoreceptors perceive the changing light condition and transform them into a molecular signal that results in the appropriate response. The photoreceptors of red/far-red light are phytochromes the dimeric proteins covalently linked with phytochromobilin that acts as a chromophore.

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 .

Phytochromes are plant, cytoplasmic photoreceptors and far red light red, which in response to a given stimulus light to undergo photoconversion active form Pfr and migrate to the nucleus. Recent studies show that phytochromes can phosphorylate a number of proteins (PKS1, Aux / IAA, cryptochromes, NDPK2) or as a result of direct interaction with the relevant nuclear proteins (PIF3, HFR1/REP/RSF1, PIF4, ELF3, ARR4) are involved in the regulation of trankrypcji genes.

Some mono- and disaccharides act as signaling molecules that regulate gene expression. In budding yeast, the glucose sensor membrane Rgt2 Snf3 and activate signaling pathways regulating the expression of genes encoding glucose transporters . GPR1 membrane glucose receptor interacting with the G protein activates a signal transduction chain comprising the adenylate cyclase and protein kinase A. Results of many studies suggest that changes in intracellular levels of glucose by heksokinazę2 ( Hxk2 ) .