Genetic and Physical Localization of the Gene Controlling Leaf Pigmentation Pattern in Medicago truncatula.

In Medicago truncatula, some ecotypes form a black or purple stain in the middle of adaxial leaf surface due to accumulation of anthocyanins. However, this morphological marker is missing in some other ecotypes, although anthocyanin biosynthesis pathway is not disrupted. Genetic analysis indicated that the lack of the leaf spot of anthocyanins accumulation is a dominant trait, which is controlled by a single gene, LPP1. Genetic mapping indicated that the LPP1 gene was delimited to a 280 kb-region on Chromosome 7. A total of 8 protein-coding genes were identified in the LPP1 locus through gene annotation and sequence analysis. Of those, two genes, putatively encoding MYB-transcriptional suppressors, were selected as candidates for functional validation.