Meyer J D F, Snook M E, Houchins K E, Rector B G, Widstrom N W, McMullen M D
Genetics Area Program, University of Missouri, Columbia, MO, 65211, USA.
Theor Appl Genet. 2007 Jun;115(1):119-28. doi: 10.1007/s00122-007-0548-7. Epub 2007 May 8.
Maysin is a naturally occurring C-glycosyl flavone found in maize (Zea mays L.) silk tissue that confers resistance to corn earworm (Helicoverpa zea, Boddie). Recently, two new maize populations were derived for high silk maysin. The two populations were named the exotic populations of maize (EPM) and the southern inbreds of maize (SIM). Quantitative trait locus (QTL) analysis was employed to determine which loci were responsible for elevated maysin levels in inbred lines derived from the EPM and SIM populations. The candidate genes consistent with QTL position included the p (pericarp color), c2 (colorless2), whp1 (white pollen1) and in1 (intensifier1) loci. The role of these loci in controlling high maysin levels in silks was tested by expression analysis and use of the loci as genetic markers onto the QTL populations. These studies support p, c2 and whp1, but not in1, as loci controlling maysin. Through this study, we determined that the p locus regulates whp1 transcription and that increased maysin in these inbred lines was primarily due to alleles at both structural and regulatory loci promoting increased flux through the flavone pathway by increasing chalcone synthase activity.
麦黄酮是一种天然存在的C - 糖基黄酮，存在于玉米（Zea mays L.）花丝组织中，可赋予对玉米穗虫（Helicoverpa zea, Boddie）的抗性。最近，培育出了两个富含高花丝麦黄酮的新玉米群体。这两个群体分别被命名为玉米外来群体（EPM）和玉米南方自交系（SIM）。采用数量性状位点（QTL）分析来确定哪些位点导致了源自EPM和SIM群体的自交系中麦黄酮水平升高。与QTL位置一致的候选基因包括p（果皮颜色）、c2（无色2）、whp1（白色花粉1）和in1（增强子1）位点。通过表达分析以及将这些位点用作QTL群体的遗传标记，测试了这些位点在控制花丝中高麦黄酮水平方面的作用。这些研究支持p、c2和whp1是控制麦黄酮的位点，而in1不是。通过这项研究，我们确定p位点调节whp1的转录，并且这些自交系中麦黄酮的增加主要是由于结构和调控位点的等位基因通过增加查尔酮合酶活性促进黄酮途径通量增加所致。
