title: 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.
abstract: 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 TT16 homologs from the allotetraploid oil crop species Brassica napus, and systematically explore their regulatory function in endothelial development. Our results indicated that all four BnTT16 genes were predominantly expressed in the early stages of seed development, but at distinct levels, and encoded functional proteins. Bntt16 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 anthocyanidin reductase (ANR) and dihydroflavonol reductase (TT3), we also determined that BnTT16 proteins played a significant role in the transcriptional regulation of five other genes involved in the PA biosynthetic pathway (P < 0.01). Moreover, we identified two genes involved in inner integument development that were strongly regulated by the BnTT16 proteins (TT2 and δ-vacuolar processing enzyme). These results will better our understanding of the precise role of TT16 in endothelial development in Brassicaceae species, and could potentially be used for the future improvement of oilseed crops.
authors: Alberta Innovates Phytola Centre, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
authors: Guanqun
authors: G
authors: Chen
authors: Wei
authors: W
authors: Deng
authors: Fred
authors: F
authors: Peng
authors: Martin
authors: M
authors: Truksa
authors: Stacy
authors: S
authors: Singer
authors: Crystal L
authors: CL
authors: Snyder
authors: Elzbieta
authors: E
authors: Mietkiewska
authors: Randall J
authors: RJ
authors: Weselake
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029688:Brassica napus / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D023281:Genomics; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009928:Organ Specificity; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D044945:Proanthocyanidins / Q000378:metabolism*; D012639:Seeds / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019076:Transgenes
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins; D044945:Proanthocyanidins; C013221:proanthocyanidin