title: Sorghum bmr6 mutant analysis demonstrates that a shared MYB1 transcription factor binding site in the promoter links the expression of genes in related pathways.
abstract: Sorghum is not only an important cereal crop but also a biofuel crop. The sorghum brown midrib mutant 6 (bmr6) has a reduced lignin content in the cell walls and vascular tissues, which could potentially be advantageous for cellulosic biofuel production. Meanwhile, both dry matter yield and plant height were decreased in the bmr6 mutant. To identify genes affected in the mutant, differential gene expression analysis was performed for bmr6 and the wild type. As a result, a total of 1,052 differentially expressed genes were detected between the two samples, of which 166 genes were downregulated and 886 genes were upregulated. Five hundred seventy-nine of the 1,052 differentially expressed genes could be assigned to 154 documented pathways. These pathways mainly included primary and secondary metabolism. Therefore, mutation of the bmr6 gene, which impaired the biosynthesis of lignin, ultimately affected the expression of these genes associated with the growth and development of sorghum. Except for the bmr6 gene, 11 key enzyme genes of monolignols biosynthesis were upregulated. Promoter analysis identified that these genes have common MYB sites. It revealed that a feedback mechanism existed in the pathway and a MYB1 transcription factor (Sb02g031190) could associate with the upregulation of these genes in sorghum. In this study, we investigated gene expressions at a global level in sorghum bmr6 mutant and provided valuable insights into the mechanisms of lignin biosynthesis.
authors.affiliation: College of Plant Science, Anhui Science and Technology University, Fengyang, People's Republic of China.
authors.forename: Jieqin
authors.initials: J
authors.lastname: Li
authors.forename: Lihua
authors.initials: L
authors.lastname: Wang
authors.forename: Qiuwen
authors.initials: Q
authors.lastname: Zhan
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Liu
authors.forename: Bisheng
authors.initials: B
authors.lastname: Fu
authors.forename: Chunming
authors.initials: C
authors.lastname: Wang
mesh_terms: D001665:Binding Sites; D018506:Gene Expression Regulation, Plant; D008031:Lignin / Q000096:biosynthesis / Q000235:genetics; D053858:Metabolic Networks and Pathways; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D045868:Sorghum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D008031:Lignin
references.citation: Annu Rev Plant Biol. 2003;54:519-46
references.pmid: 14503002
references.citation: Trends Plant Sci. 2008 Aug;13(8):415-20
references.pmid: 18650120
references.citation: Plant J. 2008 May;54(4):569-81
references.pmid: 18476864
references.citation: Theory Biosci. 2012 Dec;131(4):281-5
references.pmid: 22872506
references.citation: Phytochemistry. 2001 Aug;57(7):1069-84
references.pmid: 11430980
references.citation: Plant J. 2012 Jun;70(5):818-30
references.pmid: 22313236
references.citation: Planta. 2006 Dec;225(1):23-39
references.pmid: 16832689
references.citation: Plant Cell. 2005 Jul;17(7):2059-76
references.pmid: 15937231
references.citation: Plant Physiol. 2009 Jun;150(2):584-95
references.pmid: 19363091
references.citation: Plant Cell. 1995 Apr;7(4):407-16
references.pmid: 7773015
references.citation: J Mol Biol. 1990 Oct 5;215(3):403-10
references.pmid: 2231712
references.citation: J Exp Bot. 2008;59(14):3925-39
references.pmid: 18805909
references.citation: Plant Cell Rep. 2012 Jan;31(1):91-101
references.pmid: 21912859
references.citation: Planta. 2008 Dec;229(1):115-27
references.pmid: 18795321
references.citation: Plant J. 1998 Jun;14(5):545-53
references.pmid: 9675900
references.citation: Physiol Genomics. 2003 Jan 15;12(2):159-62
references.pmid: 12429865
references.citation: Nature. 2009 Jan 29;457(7229):551-6
references.pmid: 19189423
references.citation: Science. 1997 Oct 24;278(5338):631-7
references.pmid: 9381173
references.citation: Genetics. 2009 Feb;181(2):783-95
references.pmid: 19087955
references.citation: Curr Opin Cell Biol. 2005 Jun;17(3):316-25
references.pmid: 15901503
references.citation: Plant Cell. 2000 Dec;12(12):2383-2394
references.pmid: 11148285
references.citation: FEBS J. 2011 Jan;278(1):156-66
references.pmid: 21122072
references.citation: J Dairy Sci. 2004 Mar;87(3):637-44
references.pmid: 15202648
references.citation: Nucleic Acids Res. 2008 Dec;36(21):e141
references.pmid: 18927111
references.citation: Plant Mol Biol. 2009 Apr;69(6):685-97
references.pmid: 19116760
references.citation: Methods. 2001 Dec;25(4):402-8
references.pmid: 11846609
references.citation: J Dairy Sci. 2004 Aug;87(8):2519-26
references.pmid: 15328275
references.citation: Plant Cell. 2007 Nov;19(11):3669-91
references.pmid: 18024569