Functional Analysis of Selected Genes in Maize

PI: John F. Doebley（威斯康星大学麦迪逊分校）合作者：David M. Wills（威斯康星大学麦迪逊分校）农作物是选择性育种的产物，在这一过程中，植物育种者选择具有有用性状的基因变异，而不选择具有有害性状的变异。一般来说，数百个基因已经成为单一作物品种选择性育种的目标。在过去的十年中，在玉米驯化和改良过程中，大约有80个基因被明确确定为育种目标。目前还不清楚为什么这些玉米基因的变异特别受选择性育种的青睐，部分原因是不知道哪些有利性状受到基因变异的影响。确定受基因变异影响的特定性状对于理解玉米如何能够如此广泛地适应全球不同的条件非常重要。此外，这一信息增加了进一步适应性选择的可能性，未来气候变化要求作物采用新的生长策略，这一过程可能是必要的。该项目使用三种方法解决了确定玉米变异选择的原因和方式的问题。首先，基因表达（一种基因活性形式）的差异将在80个玉米基因的选择和未选择变体中进行检查。结果将表明选择是倾向于基因表达水平较高还是较低的变体。其次，将对选定的四个玉米基因进行详细分析，以确定它们控制的特征，重点研究与产量、收获和环境适应性相关的农艺性状。第三，鉴定四个选定基因的突变，并对突变体进行遗传研究，以了解基因功能。这些研究应该为玉米如何成为世界上最多产的农作物之一提供遗传学解释。了解遗传多样性如何产生农艺多样性对于在不断变化的世界中提高玉米的农业性能是必要的。玉米也是培养学生和未来育种人员了解进化、遗传和农业过程的优秀示范作物。作为威斯康星大学综合生物科学暑期研究计划（IBS-SRP）的一部分，本科生将接受玉米多样性研究方面的指导。IBS-SRP为来自不同背景的学生提供了研究机会，从而为科学研究提供了一个可能无法获得的介绍。项目产生的数据将在项目网站（www.panzea.org）和玉米遗传数据库www.maizegdb.org上提供。该项目开发的所有种子库存将通过玉米遗传合作库存中心（http://maizecoop.cropsci.uiuc.edu）提供。

PI: John F. Doebley (University of Wisconsin - Madison)Collaborator: David M. Wills (University of Wisconsin - Madison)Crop plants are the products of selective breeding, a process whereby plant breeders select for gene variants that confer useful traits and against variants that confer detrimental traits. Generally, hundreds of genes have been the targets of selective breeding in a single crop species. Over the last decade, approximately 80 genes have been specifically identified as targets of breeding during the domestication and improvement of maize. It is not clear why variants of these maize genes were particularly favored by selective breeding, in part because it is not known what favorable traits are affected by the gene variants. Identifying the specific traits influenced by a gene variant is important to understanding how maize has been able to adapt so widely to diverse conditions across the globe. Further, this information increases the potential for further adaptive selection, a process likely needed in the future as climate change demands new growth strategies in crops. This project addresses the problem of identifying why and how variants have been selected in maize using three approaches. First, differences in gene expression, a form of gene activity, will be examined in selected and unselected variants for each of the 80 maize genes. The results will indicate whether selection favored variants with higher or lower levels of gene expression. Second, four of the selected maize genes will be analyzed in detail to determine which characteristics they control, focusing on agronomic traits related to yield, harvest and adaptation to the environment. Third, mutations in the four selected genes will be identified and the mutants studied genetically to understand gene function.These studies should provide genetic explanations for how maize has become one of the most productive agricultural crops worldwide. Understanding how genetic diversity generates agronomic diversity is necessary to improve the agricultural performance of maize in a changing world. Maize is also an excellent model crop for training students and future breeders in understanding the processes of evolution, genetics, and agriculture. Undergraduate students will be mentored in maize diversity research as part of the Integrated Biological Sciences Summer Research Program (IBS-SRP) at the University of Wisconsin. The IBS-SRP provides research opportunities for students from diverse backgrounds, thus providing an introduction to scientific research that may not be otherwise available. Data generated by the project will be available at the project website (www.panzea.org) and the Maize Genetics Database at www.maizegdb.org. All seed stocks developed by the project will be available via the Maize Genetics Cooperation Stock Center at http://maizecoop.cropsci.uiuc.edu.