Advances in Plant Flavonoid Transport and Accumulation Mechanism
Flavonoids are polyphenols compounds produced during the secondary metabolism of plants,which are widely present in plants and have various functions.Flavonoids biosynthesis takes place at the cytosolic side of the en-doplasmic reticulum(ER),but accumulation of various flavonoids is observed in the vacuole.Efficient transport and ac-cumulation systems are therefore required to transfer flavonoids from the ER into the vacuole.Certain researches for the transport of flavonoids has been done for decades.Current research results showed that:there are three transport mechanisms in plants,including glutathione S-transferase(GST),membrane transporters,and vesicle trafficking.Here,we reviewed the three transport mechanisms and advances of plant flavonoids transport in recent years.The functional cooperation of three distinct but nonexclusive mechanisms were summarized.While the biosynthesis of the flavonoids is well characterized across species,the research on flavonoids transport and accumulation is still relatively insufficient.For better understand the flavonoids transport and accumulation mechanism in plant,the relationship between flavonoids modification and transport,flavonoids transport substrate specificity and preference,and transcriptional regulation of flavonoids transport remain deeply unexplored.