Nucleotide sequences are disclosed that may be used to impart herbicide
resistance to green plants. The sources of novel herbicide resistance were originally
isolated in mutant rice plants. The sequences impart pre-emergence resistance,
post-emergence resistance, or both pre-emergence resistance and post-emergence
resistance to multiple herbicides. To date, resistance has been demonstrated against
at least the following herbicides: imazethapyr, imazapic, imazapyr, imazamox, sulfometuron
methyl, imazaquin, chlorimuron ethyl, metsulfuron methyl, rimsulfuron, thifensulfuron
methyl, pyrithiobac sodium, tribenuron methyl, and nicosulfuron. Green plants transformed
with these sequences are resistant to these herbicides and to derivatives of these
herbicides, and to at least some of the other herbicides that normally inhibit
acetohydroxyacid synthase (AHAS), particularly imidazolinone and sulfonylurea herbicides.