Characterization of the Major Dormancy gene at qSD12 in Rice

种子休眠是一种发育受阻的状态，它促进了许多野生物种的生存，有助于农业生态系统中杂草的持续存在，并为谷类作物提供了对收获前发芽的抗性。杂草害虫和穗发芽危害给世界和美国农业造成了巨大的经济损失。为了了解胚生长是如何被阻止以维持休眠状态的，含有qSD 12的小基因组片段，对种子休眠有主要影响的数量性状位点（QTL），已经从杂草中引入到栽培稻中以表征QTL潜在基因。使用遗传学、基因组学、分子生物学和生物信息学方法的组合，新基因将被精确定位到部分高分辨率遗传图谱和特定的物理间隔，确定其是否在单个或多个种子组分组织中表达，并检查分子损伤（即，在进化和驯化过程中，DNA序列的变化）导致了功能的丧失。有了这些基因信息，后续的研究将为调节休眠获得、解除和萌发的生理和生化机制提供新的见解，为克隆与qSD 12相互作用的其他休眠位点奠定基础，并检验直向基因调节其他谷类作物或禾本科植物休眠和萌发的假设。该项目产生的协同活动是遗传学家、分子生物学家、种子科学家和育种家之间的跨学科合作，以及用于育种抗收获前发芽品种的主要休眠基因候选者。更广泛的影响包括增加代表性不足的群体参与研究的机会，以及为研究生、本科生和高中生以及高中教师提供生物学和农业课程的实践培训。

Seed dormancy is an arrested state of development that promotes the survival of many wild species, contributes to the persistence of weeds in agro-ecosystems, and provides cereal crops with resistance to pre-harvest sprouting. Weed pests and pre-harvest sprouting damage cause great economic losses in the world and US agriculture. To understand how embryo growth is arrested to maintain the dormant state, a small genomic segment containing qSD12, the quantitative trait locus (QTL) contributing a major effect on seed dormancy, has been introduced from weedy into cultivated rice to characterize the QTL underlying gene. Using a combination of genetic, genomic, molecular biological, and bioinformatic approaches, the novel gene will be pinpointed to a partial high-resolution genetic map and a particular physical interval, determined if it is expressed in single or multiple seed component tissues, and examined for molecular lesions (i.e., changes in DNA sequence) resulted in loss of the function during the evolution and domestication. With the gene information, subsequent research will rovide new insight into physiological and biochemical mechanisms regulating dormancy acquisition and releasing and germination, set the stage to clone additional dormancy loci interacting with qSD12, and test the hypothesis that orthologous genes regulate dormancy and germination in other cereal crops or grasses. Synergistic activities resulting from this project are interdisciplinary collaborations among geneticists, molecular biologists, seed scientists, and breeders, and a major dormancy gene candidate for use in breeding varieties resistant to pre-harvest sprouting. The broader impacts include enhanced opportunities for participation of underrepresented groups in research, and practical training for graduate, undergraduate, and high school students, and high school teachers in biology and agricultural programs.