Plants having increased tolerance to herbicides

A plant, or seed thereof, that expresses a mutagenized or recombinant mutated hydroxyphenyl pyruvate dioxygenase (mut-HPPD) comprising a variant of the wild-type Hordeum HPPD amino acid sequence of SEQ ID NO:2, or of the amino acid sequence of a wild-type homologue HPPD, wild-type orthologue HPPD, or wild-type paralogue HPPD thereof (i) having an amino acid sequence with at least 90% identity to SEQ ID NO:

• 2 over the entirety length, and (ii) having HPPD activity, wherein the amino acid sequence of the variant differs from that of the wild-type HPPD amino acid sequence in that it comprises at least one substitution in which:
• the amino acid corresponding to or at position 320 of SEQ ID NO:2 is Gln, His, or Tyr substituting for leucine;
• the amino acid corresponding to or at position 321 of SEQ ID NO:2 is Ala, or Gly substituting for proline;
• or the amino acid corresponding to or at position 278 of SEQ ID NO:2 is His, Asn, or Ser substituting for glutamine;
• and
• wherein said plant, expressing said mutagenized or recombinant mut-HPPD, possesses a phenotype of increased herbicide tolerance to a compound selected from 2,4-dichloro-6-fluoro-3-methylsulfonyl-N-(1-methyltetrazol-5-yl)benzamide (Inhibitor 1), 2,4-dichloro-6-fluoro-3-methylsulfanyl-N-(1-methyltetrazol-5-yl)benzamide (Inhibitor 2), or 2,4-dichloro-6-fluoro-3-methylsulfanyl-N-(2-methyl-1,2,4-triazol-3-yl)benzamide (Inhibitor 3), as compared to the corresponding wild-type variety of the plant.