A rice gene that confers broad-spectrum resistance to β-triketone herbicides.

Abstract

The genetic variation of rice cultivars provides a resource for further varietal improvement through breeding. Some rice varieties are sensitive to benzobicyclon (BBC), a β-triketone herbicide that inhibits 4-hydroxyphenylpyruvate dioxygenase (HPPD). Here we identify a rice gene, <i>HIS1</i> (<i>HPPD INHIBITOR SENSITIVE 1</i>), that confers resistance to BBC and other β-triketone herbicides. We show that <i>HIS1</i> encodes an Fe(II)/2-oxoglutarate-dependent oxygenase that detoxifies β-triketone herbicides by catalyzing their hydroxylation. Genealogy analysis revealed that BBC-sensitive rice variants inherited a dysfunctional <i>his1</i> allele from an <i>indica</i> rice variety. Forced expression of <i>HIS1</i> in <i>Arabidopsis</i> conferred resistance not only to BBC but also to four additional β-triketone herbicides. <i>HIS1</i> may prove useful for breeding herbicide-resistant crops.