TALEN-mediated Mutagenesis of COMT in Sugarcane Improves Cell Wall Decomposition for Ethanol Production

Advanced biofuel conversion technology uses sucrose from stems as well as cell wall-bound sugars from sugarcane (Saccharum spp.) for ethanol production. Although the process is relatively efficient, reduction of lignin content can still significantly improve the conversion of plant biomass into ethanol.

Conventional mutagenesis is not expected to confer reduction in lignin content in sugarcane due to its high polyploidy. Hence, the team of Hui Zhang of the Chinese Academy of Sciences used transcription activator-like effector nuclease (TALEN) to induce mutations in a highly conserved region of the caffeic acid O-methyltransferase (COMT) of sugarcane.

Targeted COMT mutations were identified in up to 74% of the lines. Mutation frequencies among the mutant lines were found to be positively correlated to lignin reduction. Events with mutations displayed a 29–32% reduction of the lignin content compared to controls.

Further analysis displayed similar peak patterns between primary COMT mutants and their vegetative progenies, suggesting that TALEN-mediated mutations can be transmitted via vegetative progenies. This is the first report on genome editing in sugarcane.

For more information, read the article in Plant Molecular Biology.