The role of anthocyanins in plant stress response

Antocijani su crveno, ružičasto do plavo obojeni biljni pigmenti koji se ubrajaju među biljne fenolne spojeve. Nakupljaju se u vakuoli biljne stanice te je poznato da daju boju plodovima i laticama te privlače oprašivače odnosno rasprostranjivače. Također, primjećeno je da se antocijani sintetiziraju pri stresnim uvjetima u okolišu, kao što su primjerice niska temperatura, vodni stres i jako osvjetljenje, te se privremeno nakupljaju u stanici. U nizu provedenih istraživanja pretpostavljena je njihova uloga u zaštiti od abiotičkog i biotičkog stresa. Postoji više različitih hipoteza koje govore da mogu imati ulogu u zaštiti od fotoinhibicije, zaštiti od smrzavanja, zaštiti od UVB zračenja, zaštiti od herbivora ili da imaju ulogu antioksidansa. Međutim, dosada niti jedna hipoteza nije eksperimentalno potvrđena iako se najvjerodostojnijijom čini pretpostavka da štite fotosintetski aparat od fotoinhibicije. Stoga su potrebna su daljnja istraživanja kako bi se razjasnila uloga antocijana u stresnim uvjetima kod biljaka.Anthocyanins are phenolic plant pigments that may appear red, blue or purple. They are water-soluble and are found in the vacuoles of plant cells. The coloration of petals and fruits of numerous species, which is due to anthocyanins, helps those species attract pollinators and seed dispersers. However, it appears as though anthocyanins should have a role in protecting the plant from stress because it was found that they are synthesized in stressful conditions, for example during drought, cold temperatures or in high light conditions. Numerous studies were conducted but it was never experimentally confirmed what exactly was the role of anthocyanins in plant stress. Possible explanations include protection from photoinhibition, protection from freezing, protection from UVB radiation, protection from herbivores and protection from oxidative stress. The hypothesis that they serve as protectors from photoinhibition of photosynthetic apparatus seems most plausible at the moment. Further research is needed in order to discover the role of anthocyanins in plant stress response