MYB31/MYB42 Syntelogs Exhibit Divergent Regulation of Phenylpropanoid Genes in Maize, Sorghum and Rice.
ZmMYB31 and ZmMYB42 are R2R3-MYB transcription factors implicated in the regulation of phenylpropanoid genes in maize. Here, we tested the hypothesis that the regulatory function of MYB31 and MYB42 is conserved in other monocots, specifically in sorghum and rice. We demonstrate that syntelogs of MYB31 and MYB42 do bind to phenylpropanoid genes that function in all stages of the pathway and in different tissues along the developmental gradient of seedling leaves. We found that caffeic acid O-methyltransferase (COMT1) is a common target of MYB31 and MYB42 in the mature leaf tissues of maize, sorghum and rice, as evidenced by Chromatin immunoprecipitation (ChIP) experiments. In contrast, 4-coumarate-CoA ligase (4CL2), ferulate-5-hydroxylase (F5H), and caffeoyl shikimate esterase (CSE), were targeted by MYB31 or MYB42, but in a more species-specific fashion. Our results revealed MYB31 and MYB42 participation in auto- and cross-regulation in all three species. Apart from a limited conservation of regulatory modules, MYB31 and MYB42 syntelogs appear to have undergone subfunctionalization following gene duplication and divergence of maize, sorghum, and rice. Elucidating the different regulatory roles of these syntelogs in the context of positive transcriptional activators may help guide attempts to alter the flux of intermediates towards lignin production in biofuel grasses.
Department of Biological Sciences, University of Toledo, Toledo, OH 43606 USA.
Tina
T
Agarwal
Center for Applied Plant Sciences (CAPS) and Department of Molecular Genetics, The Ohio State University, 1060 Carmack Rd, 012 Rightmire Hall, Columbus, OH 43210, USA.
Erich
E
Grotewold
Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, 43210 USA.|Department of Physiology and Cell Biology and The Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio, 43210 USA.
Andrea I
AI
Doseff
Department of Biological Sciences, University of Toledo, Toledo, OH 43606 USA.
John
J
Gray
D019143:Evolution, Molecular; D020440:Gene Duplication; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D008780:Methyltransferases / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D025941:Protein Interaction Mapping; D017423:Sequence Analysis, RNA; D045868:Sorghum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D003313:Zea mays / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D010940:Plant Proteins; D014157:Transcription Factors; D008780:Methyltransferases; C019608:caffeate O-methyltransferase