Modifying dhurrin metabolism in sorghum
A genetic mutant of sorghum that does not accumulate dhurrin was reported by Blomstedt et al. (2012). This mutant was described as a P414L mutation in CYP79A1 but the mutant was reported to grow more slowly than wild-type plants.
We have conducted forward genetic screens of a chemically mutagenized sorghum population and identified several new genetic variants that disrupt dhurrin metabolism. Whole genome resequencing experiments demonstrated that one of these variants harbored a C493Y mutation in CYP79A1 that disrupts dhurrin biosynthesis. Plants with this mutation do not exhibit a slow-growth phenotype. This mutation may provide a new genetic resource for eliminating dhurrin production in sorghum to improve feed, forage, and bioenergy feedstock value.