Overexpression of a foxtail millet Acetyl-CoA carboxylase gene in maize increases sethoxydim resistance and oil content

Abstract

Acetyl-coenzyme A carboxylase (ACCase) plays a crucial role in fatty acid metabolism in plants, catalyzing the carboxylation of acetyl-CoA to produce malonyl-CoA. In grasses, the plastids ACCases are critical determinants of plant sensitivity to herbicide classes cyclohexanediones (CHDs) and aryloxyphenoxy propionates (APPs). We transformed the full-length cDNA of a plastid ACCase gene from foxtail millet (Setaria italica) line Chum BC6-1, which is highly resistant to sethoxydim, into maize (Zea mays L.) drived by a ubiquitin promoter. The substantial results indicated that the sethoxydim resistance of transgenic plants is increased, with a damage index of 33%, much lower than that of 97% in the untransformed plants. Additionally, the oil content of transgenic maize seeds was 24 to 65% higher than that of untransformed seeds. These results indicate that the ACCase transgenic plants can be used to develop new maize hybrids that are tolerant to herbicide CHDs with high oil content.

Key words: Zea mays, Acetyl-coenzyme A carboxylase (ACCase), oil content, transgenic plants, Agrobacterium tumefaciens