Bayer Cropscience S.a.

Aventis Cropscience S.a.

Michel Matringe

Alain Sailland

Ken Pallett

Anne Rolland

Pascal Rippert

The invention concerns novel enzymes having an arogenate dehydrogenase activity, in particular arogenate dehydrogenase enzymes of plants, and the genes encoding said enzymes. The inventive arogenate dehydrogenase enzymes catalyze the last stage of the metabolic pathway of tyrosine biosynthesis, and constitute, as such, potential targets of herbicides. Hence the invention also concerns a method for identifying herbicide compounds targeting said enzymes, said herbicide compounds preventing tyrosine biosynthesis by being fixed on said enzymes. The invention further concerns transgenic plants tolerant to herbicide compounds targeting an enzyme involved in the tyrosine biosynthesis pathway, in particular an enzyme involved in the transformation of L-tyrosine prephenate, in particular an arogenate dehydrogenase enzyme. Said plants become tolerant by expression in their tissues of a prephenate dehydrogenase enzyme, said enzyme being insensitive to said herbicide compounds and enabling the plant to synthetize tyrosine despite being treated with said herbicide compounds.

Methods for identifying herbicidal compounds

An isolated gene from Pseudomonas is described which expresses a hydoxy phenyl pyruvate dioxygenase. Also described are chimeric genes for introduction into plants to overexpress a hydoxy phenyl pyruvate dioxygenase and produce plants which are tolerant to herbicides.

DNA sequence of a gene of hydroxy-phenyl pyruvate dioxygenase and production of plants containing a gene of hydroxy-phenyl pyruvate dioxygenase and which are tolerant to certain herbicides

Growing community of inventors

Lyons, France

Michel Matringe