Get access

Identification of differentially expressed genes in sorghum (Sorghum bicolor) brown midrib mutants

Authors

  • Li Yan,

    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    2. USDA-ARS Plant Science Research Laboratory, Stillwater, OK 74075, USA
    Search for more papers by this author
    • These authors equally contributed to this work.

  • Shuwei Liu,

    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    Search for more papers by this author
    • These authors equally contributed to this work.

  • Shuangyi Zhao,

    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    2. USDA-ARS Plant Science Research Laboratory, Stillwater, OK 74075, USA
    Search for more papers by this author
  • Yali Kang,

    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    Search for more papers by this author
  • Duoxiang Wang,

    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    Search for more papers by this author
  • Tongwei Gu,

    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    Search for more papers by this author
  • Zhanguo Xin,

    1. Plant Stress and Germplasm Development Unit, USDA-ARS, Lubbock, TX 79415, USA
    Search for more papers by this author
  • Guangmin Xia,

    Corresponding author
    1. The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, P.R. China
    Search for more papers by this author
  • Yinghua Huang

    Corresponding author
    1. USDA-ARS Plant Science Research Laboratory, Stillwater, OK 74075, USA
    Search for more papers by this author

Corresponding authors,
e-mail: xiagm@sdu.edu.cn e-mail: yinghua.huang@ars.usda.gov

Abstract

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.

Ancillary