Will the Amaranthus tuberculatus Resistance Mechanism to PPO-Inhibiting Herbicides Evolve in Other Amaranthus Species?

Figure 2

(a) Partial PPX2 gene structure showing exon/intron positions and sizes. (b) Alignment of exon 9 from different Amaranthus species. The consensus nucleotide sequence and translated amino acid sequence are at the top. Conserved nucleotides are represented by dots. The boxed codon indicates the site of the Gly210 deletion mutation that is present in the PPO-resistant biotype of A. tuberculatus (GenBank DQ394876) and not in the wild-type (GenBank DQ394875) or any of the other species. Sequences that are cleaved in the PCR-RFLP assay are indicated by the shaded box which depicts the EciI recognition site. An inferred amino acid change of Gly211 to Val211 is also shown that results from a G to T nucleotide polymorphism in the Gly211 codon in the sequence of A. acanthochiton. The PPX2 sequence of A. hypochondriacus is from GenBank (EU024569).