Journal of Genetics

, Volume 94, Issue 3, pp 445–452 | Cite as

Map-based cloning and expression analysis of BMR-6 in sorghum

  • QIUWEN ZHANEmail author


Brown midrib mutants in sorghum are associated with reduced lignin content and increased cell wall digestibility. In this study, we characterized a bmr-6 sorghum mutant, which shows reddish pigment in the midrib and stem after the fifth-leaf stage. Compared to wild type, Kalson lignin content of bmr-6 is decreased significantly. We used histological analysis to determine that the mutant exhibited a modified pattern of lignin staining and found an increased polysaccharide content. We cloned BMR-6 gene, a gene encoded a cinnamyl alcohol dehydrogenase (CAD), using a map-based cloning approach. Genetic complementation confirmed that CAD is responsible for the BMR-6 phenotype. BMR-6 gene was expressed in all tested sorghum tissues, with the highest being in midrib and stem. Transient expression assays in Nicotiana benthamiana leaves demonstrated cytomplasmic localization of BMR-6. We found that the expression level of bmr-6 was significantly decreased in the mutant but expression of SbCAD3 and SbCAD5 were significantly increased. Our results indicate that BMR-6 not only affects the distribution of lignin but also the biosynthesis of lignin in sorghum.


bmr-6 cinnamyl alcohol dehydrogenase lignin biosynthesis sorghum 



This work was supported by grants from the National Natural Science Foundation (31301383 and 31071470), the Key-construction Subject Plan of Anhui Province, the Anhui Science and Technology University Research Programme (ZRC2013371), and the Planning Subject of ‘the Twelfth Five Year Plan’ in the National Science and Technology for the Rural Development in China (2011BAD17B03).


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© Indian Academy of Sciences 2015

Authors and Affiliations

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    • 1
    • 1
    Email author
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  1. 1.College of AgricultureAnhui Science and Technology UniversityFengyangPeople’s Republic of China

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