Abstract
To adapt to low soil fertility, white lupin (Lupinus albus L.) produces cluster roots that are characterized by the synchronous and determinate development of rootlets that arise from pericycle and by the secretion of organic acid and acid phosphatase. To understand the molecular mechanisms controlling cluster root development, one lupin MYB gene, named LaMYB1, was isolated from the young cluster root-derived cDNA library. Homology research showed LaMYB1 made a different cluster with well-characterized R2R3-MYB genes, indicating that LaMYB1 is a novel R2R3-MYB gene. LaMYB1 expressed mainly in roots and faintly in nodules, leaves, flowers and shoot apex. White lupin hairy roots transformed with the LaMYB1 promoter::GUS construct showed that the transcription of this gene was specific to pericycle, suggesting the correlation to lateral root development.
