Isolation and structural analysis of the Bx6 and Bx7 genes controlling the biosynthesis of benzoxazinoids in rye (Secale cereale L.)

Abstract

Benzoxazinoids (BXs) are plant secondary metabolites, first discovered in the 1950s, which are synthesized in many monocotyledonous species from the Poaceae family and in several dicotyledonous plants. They constitute a significant element of the plant’s defence mechanism against both biotic (pests and diseases) and abiotic (elevated salinity, heavy metals) stresses. The aim of this research was to gain more information on the genetic background of BXs biosynthesis in rye (Secale cereale L.) by isolating and sequencing the ScBx6L318 and ScBx7L318 genes encoding 2-oxoglutarate-dependent dioxygenase and 7-O-methyltransferase, respectively. Using the modified Amplicon Express method, BAC clones containing the ScBx6L318 and ScBx7L318 genes were isolated and sequenced. The similarity between the ScBx6L318 and ZmBx6 genes were, correspondingly, 78% and 68% in the coding sequence (cds) and the amino acid sequence (AA). A lesser similarity was found between the ScBx7L318 and ZmBx7 genes (72% and 45% at the cds and AA levels, respectively).