Agrobacterium T‐DNA gene 1 codes for tryptophan 2‐monooxygenase activity in tobacco crown gall cells

Abstract
Cloned tobacco crown gall tissue induced by the Agrobacterium tumefaciens C58 T‐DNA mutant pGV3132, defective for the T‐DNA‐encoded amihydrolase (iaaH), accumulates about 1000‐times more indole‐3‐acet‐amide (IAM) when compared to untransformed tobacco callus and crown gall tissue induced by a T‐DNA mutant defective for gene 1. In vitro experiments demonstrated that this IAM accumulation is correlated with the active conversion of Trp into IAM. The results presented in this report provide biochemical evidence that the T‐DNA gene 1 encodes a tryptophan 2‐monooxygenase (iaaM) activity in transformed plant cells. This gene cooperates with the gene 2‐encoded amidohydrolase (iaaH) in the T‐DNA‐controlled indole‐3‐acetic acid (IAA) biosynthesis pathway in crown gall cells.