Allele Specific Gene Regulation in Maize Floral Organs

玉米花器官中等位基因特异性基因调控

• 批准号: 9601285
• 负责人: Thomas Peterson
• 金额: $ 37.2万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9601285&HistoricalAwards=false
• 关键词: Allele; Specific; Gene; Regulation; Maize

9601285 Peterson The maize P gene encodes a Myb-homologous transcriptional regulator of three genes for flavonoid pigment biosynthesis in certain maize floral organs. The P-rr allele specifies pigmentation of both the kernel pericarp and cob glumes, while the P-wr allele pigments the cob glumes but not the kernel pericarps. The mechanism(s) leading to organ-specific expression of the P-wr allele will be investigated. It has been found that both tissues contain P-wr transcripts although the pericarps are colorless and the cob glumes are red. It has also been determined that the proteins encoded by these two alleles differ at two positions outside the Myb DNA binding domain and by a truncation and replacement at the C-terminus. A particle-gun based transient assay system will be used to determine which changes in the P-wr protein are responsible for organ-specific expression. In addition to transient assays the in vivo expression pattern of the P-wr allele will be studied by expressing the P-wr cDNA in transgenic plants. It has been found that the P-wr locus contains a repetitive DNA consisting of approximately 5 copies of a 12.6 kb DNA sequence and the genomic organization of the locus will be further investigated. The functional P-wr gene will be identified by the use of a Ds insertion. cDNA clones from two additional P gene alleles will be sequenced and their responsiveness to UFO, a trans-modifier of P-wr expression, will be studied. %%% The results of this study will help to elucidate fundamental regulatory mechanisms which produce specific patterns of gene expression during plant development. ***

9601285 Peterson玉米P基因编码三个基因的Myb同源转录调节因子，用于某些玉米花器官中的类黄酮色素生物合成。P-rr等位基因指定了籽粒果皮和穗轴颖片的色素沉着，而P-wr等位基因只着色穗轴颖片而不着色籽粒果皮。将研究导致P-wr等位基因器官特异性表达的机制。已经发现，尽管果皮是无色的，穗轴颖是红色的，但这两种组织都含有P-wr转录本。还已经确定，由这两个等位基因编码的蛋白质在Myb DNA结合结构域之外的两个位置处不同，并且在C-末端处截短和替换。将使用基于粒子枪的瞬时测定系统来确定P-wr蛋白中的哪些变化是器官特异性表达的原因。除了瞬时测定外，还将通过在转基因植物中表达P-wr cDNA来研究P-wr等位基因的体内表达模式。已经发现P-wr基因座含有由大约5个拷贝的12.6kb DNA序列组成的重复DNA，并且将进一步研究该基因座的基因组结构。将通过使用Ds插入来鉴定功能性P-wr基因。将对来自另外两个P基因等位基因的cDNA克隆进行测序，并研究它们对UFO（P-wr表达的反式修饰物）的反应。 本研究的结果将有助于阐明植物发育过程中产生特定基因表达模式的基本调控机制。 ***