2004 Volume 29 Issue 1 Pages 1-5
Here, we cloned and sequenced fragments encoding ALS genes from biotypes of Limnophila sessiliflora susceptible and resistant to SU-herbicide. Comparisons of deduced amino acid sequences and secondary protein structures were implemented. The results showed that Pro was substituted with Gln and a G-X-X-P motif was abolished in Domain A of resistant ALS, and the secondary protein structure was converted from extended strands to an α-helix around Domain A by the Pro mutation. We suggest that resistance to SU-herbicides is caused by the mutation of ALS and conformational change of its secondary structure.