Expanding the maize domestication gene network: from phenotype to gene

像其他农作物一样，玉米或玉米是由一种野生植物驯化而来的。玉米大约在10,000年前在墨西哥南部被驯化。驯化深刻地改变了玉米植株的结构和外观，将一个低产的野生物种变成了今天美国种植的最高产的作物。这项研究将阐明其中一些植物结构变化的遗传基础。具体地说，这项研究将确定其中两个基因，这些基因在驯化过程中将带花粉的雄穗转化为带种子的穗。这种将流苏转化为穗的机制是使玉米成为当今世界种植的高产作物的核心机制。一旦确定了这两个新基因，这项研究还将剖析这些基因如何与其他已知基因协同工作，形成控制玉米植株结构的“基因网络”。网络中的每个基因就像是一台由多个齿轮组成的复杂机器中的一个单独的齿轮，这些齿轮一起工作。了解这一基因网络将有助于植物育种者进一步改良玉米。为了超越玉米遗传学社区，该项目将通过四种方式与更广泛的社会接触：(1)发展关于作物驯化的公共宣传和教育展示；(2)为美国和墨西哥的植物科学家建立年度研讨会；(3)培训来自弱势背景的本科生；(4)培训研究生有效地进行科学研究交流。这项研究将更好地定义基因网络，该基因网络被改造为从其野生祖先teosinte生产驯化玉米。此前，已鉴定出几个与teosinte转化玉米有关的基因：调节植物和花序结构的teosinte分支1(Tb1)；调节穗结构的teosinte颖片结构1(Tga1)；调节植物结构的草分蘖1(Gt1)；以及影响耳朵结构的tb1增强子(etb1.2)。这四个基因是控制植物和花序结构的玉米基因网络的成员。该项目的重点将是将teosinte初级分枝顶端的雄花(雄穗)转化为玉米的雌花(穗)。该项目的目标是：(1)将一个称为stam2.1的数量性状座位(QTL)精细定位到其下位基因，(2)将第二个QTL(称为stam1.1)精细定位到其下位基因，以及(3)在表型和基因表达水平上表征stant1.1和stant2.1与tb1的相互作用。这项研究将增加对驯化和植物发育的遗传控制的理解。为了让更广泛的社区参与进来，将开展四项活动。(1)将为美国和墨西哥的植物科学家举办年度研讨会。(2)每年培养1名贫困本科生。(3)威斯康星大学研究生将开发和展示作物驯化的“探险站”，以向公众宣传。(4)将开发一门研究生级别的课程，向广大听众进行有效的演讲。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Like other crop plants, corn or maize was domesticated from a wild plant species. Corn was domesticated approximately 10,000 years ago in southern Mexico. Domestication profoundly transformed the structure and appearance of the corn plant, converting an unproductive wild species into the most highly productive crop grown in the US today. The research will elucidate the genetic basis for some of these changes in plant structure. Specifically, the research will identify two of the genes that converted pollen bearing tassels into seed bearing ears during domestication. This conversion of tassels into ears is central to the mechanism that made corn a highly productive crop grown throughout the world today. Once the two new genes are identified, the research will also dissect how these genes work in concert with other known genes to form a “gene network” controlling the structure of the maize plant. Each gene in the network is like an individual gear in a complex machine of many gears that work together. Understanding this gene network will facilitate the efforts of plant breeders to improve maize even more. To reach beyond the maize genetics’ community, this project will engage the broader society in four ways: (1) Develop public outreach and education displays on crop domestication, (2) establish an annual workshop for US and Mexican plant scientists, (3) train undergraduate students from disadvantaged backgrounds, and (4) train graduate students in effective communication of scientific research.This research will better define the gene network that was modified to produce domesticated maize from its wild progenitor, teosinte. Previously, several genes contributing to the transformation of teosinte into maize have been identified: teosinte branched 1 (tb1) that regulates plant and inflorescence structure; teosinte glume architecture 1 (tga1) that regulates ear structure; grassy tillers 1 (gt1) that regulated plant architecture; and enhancer of tb1 (etb1.2) that affects ear structure. These four genes are members of a maize gene network that controls plant and inflorescence architecture. The project will focus on the conversion of the staminate inflorescences (tassels) at the tips of primary branches in teosinte into the pistillate inflorescences (ears) in maize. The aims of the project are: (1) fine-map a quantitative trait locus (QTL) called stam2.1 to its underlying gene, (2) fine-map a second QTL called stam1.1 to its underlying gene, and (3) characterize the interactions of stam1.1 and stam2.1 with tb1 at the phenotypic and gene expression levels. The research will add to the understanding of domestication and the genetic control of plant development. To engage the broader community, four activities will be undertaken. (1) An annual workshop for plant scientists in the US and Mexico will be organized. (2) One undergraduate student from a disadvantaged background will be trained each year. (3) UW Graduate students will develop and present “exploration stations” on crop domestication for public outreach. (4) A graduate level course on giving effective lectures to large audiences will be developed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.