Molecular Basis of Long-distance Transport of Defense Compounds in Seeds

Transport systems in plants are vital for the transfer of defense compounds that protect important tissues, which was exhibited by Arabidopsis' translocation of glucosinolates to seeds during maturation period. The molecular basis of this translocation has not yet been explained. Thus, Hussam Hassan Nour-Eldin from the University of Würzburg and team identified and characterized two nitrate/peptide transporters GTR1 and GTR2 as high-affinity, proton-dependent glucosinate-specific transporters.

They found that the gtr1gtr2 double mutant did not have an increase in the amount of glucosinates in seeds but had over-accumulation in source tissues such as leaves and silique walls. This implies that both transporters localized in the plasma membranes are necessary for long-distance transfer of glucosinates. The authors proposed that GTR1 and GTR2 are involved in the transport of glucosinates from the apoplasm to the phloem. Identification of glucosinate transporters has agricultural potential as a way to control allocation of defense compounds in tissue-specific manner.

Read more about the study at http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11285.html.