The Rhizobium strain Ngr234 Nod DA gene product responds to activation by the simple phenolic compounds vanillin and isovanillin present in wheat seedling extracts

Abstract

Vanillin and isovanillin are present in extracts of wheat seedlings and interact with the nodulation (nod) gene nodDl from Rhizobium strain NGR234 to induce expression of R, leguminosarum bv. trifolii nod genes. Seven varieties of Australian wheat were examined. Vanillin, isovanillin, or both were present in five of the varieties tested. Assays of a wide range of authentic flavonoid and other phenolic compounds for transcriptional induction of the same nodAlacZ fusion revealed that a hydroxyl group para to an electron-withdrawing group and/or the presence of a cluster of oxygen functions are the prime structural requisites for transcriptional activation of NodDl-activated nod genes. Show more