These authors equally contributed to this work.
Identification of differentially expressed genes in sorghum (Sorghum bicolor) brown midrib mutants
Article first published online: 20 JUN 2012
Copyright © Physiologia Plantarum 2012
Volume 146, Issue 4, pages 375–387, December 2012
How to Cite
Yan, L., Liu, S., Zhao, S., Kang, Y., Wang, D., Gu, T., Xin, Z., Xia, G. and Huang, Y. (2012), Identification of differentially expressed genes in sorghum (Sorghum bicolor) brown midrib mutants. Physiologia Plantarum, 146: 375–387. doi: 10.1111/j.1399-3054.2012.01646.x
- Issue published online: 8 NOV 2012
- Article first published online: 20 JUN 2012
- Accepted manuscript online: 11 MAY 2012 01:07PM EST
- Received 22 November 2011; revised 15 March 2012
Sorghum, a species able to produce a high yield of biomass and tolerate both drought and poor soil fertility, is considered to be a potential bioenergy crop candidate. The reduced lignin content characteristic of brown midrib (bmr) mutants improves the efficiency of bioethanol conversion from biomass. Suppression subtractive hybridization combined with cDNA microarray profiling was performed to characterize differential gene expression in a set of 13 bmr mutants, which accumulate significantly less lignin than the wild-type plant BTx623. Among the 153 differentially expressed genes identified, 43 were upregulated and 110 downregulated in the mutants. A semi-quantitative RT–PCR analysis applied to 12 of these genes largely validated the microarray analysis data. The transcript abundance of genes encoding l-phenylalanine ammonia lyase and cinnamyl alcohol dehydrogenase was less in the mutants than in the wild type, consistent with the expectation that both enzymes are associated with lignin synthesis. However, the gene responsible for the lignin synthesis enzyme cinnamic acid 4-hydroxylase was upregulated in the mutants, indicating that the production of monolignol from l-phenylalanine may involve more than one pathway. The identity of the differentially expressed genes could be useful for breeding sorghum with improved efficiency of bioethanol conversion from lignocellulosic biomass.