Abstract
White lupin has developed a complex strategy to survive in soils with low availability of nutrients. This behavior involves the modification of root architecture with the formation of cluster roots and the release of root exudates, mainly organic acids and flavonoids. These compounds can mobilize sparingly available nutrients in soils, such as iron and phosphorus, via complexation, ligand exchange, and in the case of flavonoids, reduction/complexation. They can also influence the biological characteristics of the rhizosphere, affecting the activity of the microorganisms.In this work we have physiologically characterized the exudation of genistein from proteoid roots. The gene involved in this process has been isolated via cDNA-AFLP and it has been named LaMATE2 which belongs to the MATE transporter family. The expression of this gene was reduced in knock down mutant plants, which also showed decreased genistein exudation. Expression in yeast cells allowed the characterization of transport activity. The results show that LaMATE2 is a genistein transporter, involved in the exudation processes of flavonoids