Isolation and characterization of a cDNA encoding polyketide reductase in Lotus japonicus
Leguminous plants have a unique pathway for production of 5-deoxy-type flavonoids and isoflavonoids that is distinct from the general flavonoid pathways. 5-Deoxy(iso)flavonoids are believed to play important eco-physiological roles as antimicrobial compounds and symbiotic signals toward rhizobia. The branching point of the 5-deoxyflavonoid pathway is the formation of the deoxy-type chalcone (isoliquiritigenin), which is catalyzed by the co-action of chalcone synthase and polyketide reductase (PKR). In the course of the comparative genomics of legume-specific genes, we cloned a putative cDNA for PKR (<i>cPKR1</i>) of a model legume <i>Lotus japonicus</i> (Regel) K. Larsen. Genomic Southern analysis showed that <i>L. japonicus</i> has a gene family composed of two to four paralogous <i>PKR</i> genes. The overexpression of <i>cPKR</i>1 in a red-flowered cultivar of petunia, "Polo Red Target", reduced anthocyanin accumulation and caused the formation of isoliquiritigenin and its putative derivatives. These results suggested that <i>PKR1</i> encodes a PKR that functions <i>in planta</i>.
- Plant biotechnology
Plant biotechnology 23(5), 509-513, 2006-12-01
Japanese Society for Plant Cell and Molecular Biology