Location: Grain, Forage & Bioenergy Research
Title: Sorghum Brown Midrib Mutants, Tools to Improve Biomass for Biofuels Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 21, 2009
Publication Date: August 11, 2009
Citation: Sattler, S.E., Funnell-Harris, D.L., Pedersen, J.F. 2009. Sorghum Brown Midrib Mutants, Tools to Improve Biomass for Biofuels. Meeting Abstract. Oral presentation to be given at Great Plains Sorghum Conference, Amarillo, TX, Aug. 11-12, 2009. Technical Abstract: To improve sorghum for cellulosic bioenergy uses, brown midrib mutants are being investigated for their ability to increase the conversion efficiency of biomass. brown midrib 6 and 12 (bmr6 and 12) mutants affect monolignol biosynthesis resulting in reduced lignin content and altered lignin composition in sorghum. A candidate gene approach was taken to identify the bmr6 mutation, and a nonsense mutation was discovered within a gene encoding an evolutionarily conserved group of cinnamyl alcohol dehydrogenases (CADs). Bmr12 was previously identified as encoding caffeic acid-O-methyltransferase (COMT). Near-isogenic lines containing either mutant or both mutants were constructed in several sorghum varieties including Atlas, Wheatland and Tx430. The effects of bmr6 and bmr12 have been comprehensively characterized using chemistry, molecular biology, microscopy and genomics. Together these data demonstrate the impact bmr-6 and bmr-12 have on lignin composition, cell wall architecture, gene expression and plant physiology across three distinct genetic backgrounds, and the potential of brown midrib mutants to improve ethanol conversion efficiency of biomass.