Brassica napus TT16 homologs with different genomic origins and expression levels encode proteins that regulate a broad range of endothelium‐associated genes at the transcriptional level. (14th March 2013)

• Record Type: Journal Article
• Authors: Chen, Guanqun; Deng, Wei; Peng, Fred; Truksa, Martin; Singer, Stacy; Snyder, Crystal L.; Mietkiewska, Elzbieta; Weselake, Randall J.
• Is Part Of: Plant journal. Volume 74:Number 4(2013:May)
• Page Start: 663
• Page End: 677
• Publication Date: 2013-03-14
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12151
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12151-abs-0001"> <title>Summary</title> <p>The transcription factor TRANSPARENT TESTA 16 (TT16) plays an important role in endothelial cell specification and proanthocyanidin (PA) accumulation. However, its precise regulatory function with regard to the expression of endothelial‐associated genes in developing seeds, and especially in the PA‐producing inner integument, remains largely unknown. Therefore, we endeavored to characterize four <italic>TT16</italic> homologs from the allotetraploid oil crop species <italic>Brassica napus</italic>, and systematically explore their regulatory function in endothelial development. Our results indicated that all four <italic>BnTT16</italic> genes were predominantly expressed in the early stages of seed development, but at distinct levels, and encoded functional proteins. <italic>Bntt16</italic> RNA interference lines exhibited abnormal endothelial development and decreased PA content, while PA polymerization was not affected. In addition to the previously reported function of TT16 in the transcriptional regulation of <italic>anthocyanidin reductase</italic> (<italic>ANR</italic>) and <italic>dihydroflavonol reductase</italic> (<italic>TT3</italic>), we also determined that BnTT16 proteins played a significant role in the transcriptional regulation of five other genes involved in the PA biosynthetic pathway (<italic>P </italic><<italic> </italic>0.01). Moreover, we identified two genes involved in inner integument development that were strongly regulated by the BnTT16 proteins (<italic>TT2</italic> and <italic>δ‐vacuolar processing enzyme</italic>). These results will better our understanding of the precise role of <italic>TT16</italic> in endothelial development in Brassicaceae species, and could potentially be used for the future improvement of oilseed crops.</p> </abstract>