CAREER: Molecular Characterization of the Vernalization-Responsive Block to Flowering in Winter-Annual Arabidopsis

职业：冬季一年生拟南芥开花春化反应块的分子表征

• 批准号: 0447583
• 负责人: Scott Michaels
• 金额: $ 80万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0447583&HistoricalAwards=false
• 关键词: CAREER; Molecular; Characterization; Vernalization; Responsive

To maximize reproductive success, plants have evolved mechanisms to regulate flowering time in response to both endogenous and environmental cues. In temperate climates, the prolonged cold temperature of winter provides a seasonal landmark for biennial and winter-annual plants. These species (which include many crop plants) contain a block to flowering such that flowering is prevented prior to winter and promoted in the spring. The promotion of flowering by prolonged cold treatment (as winter) is known as vernalization. Significant headway has been made in understanding the process of vernalization in the model plant Arabidopsis thaliana. In Arabidopsis, vernalization is caused by the interaction of two genes, FLOWERING LOCUS C (FLC), which acts to block flowering, and FRIGIDA (FRI), which is required for high levels of FLC expression. Cold causes an epigenetic repression of FLC gene expression, likely at the level of chromatin modification via histone acetylation. To dissect the regulatory interactions between FLC and FRI, an exhaustive mutant screen has been conducted. This screen led to the isolation of genes that are required for the upregulation of FLC by FRI (termed FS genes). The purpose of this proposal is to characterize the role of the FS genes in flowering-time regulation, using genetic, molecular genetic, and biochemical approaches. These studies will primarily involve: 1) double mutant analyses to characterize the genetic relationships among the various FS genes; 2) yeast two-hydrid screens to identify interactors among the various FS proteins; and 3) microarray analyses to isolate downstream targets of the FS gene products. The role of FS in other early-flowing accessions of Arabidopsis will also be examined.Broader Impacts: Because changes in gene expression through chromatin modification have been documented in a broad range of eukaryotes, including yeast, Drosophila, C. elegans, and humans, there is a high likelihood that this research will provide new knowledge that will be of broad scientific interest. This work also has potential agricultural applications, inasmuch as most crop species are biennials and the ability to manipulate their flowering time might provide avenues for crop improvement. In terms of human resources, the research will provide a fertile training ground for undergraduates, graduate students and postdoctoral fellows. Plant-development education modules will be also developed for both undergraduate genetics students and the public at large.

为了最大限度地繁殖成功，植物已经进化出调节开花时间的机制，以响应内源和环境信号。 在温带气候中，冬季持续寒冷的气温为二年生植物和冬季一年生植物提供了季节性标志。 这些物种（包括许多农作物）含有开花障碍，使得开花在冬季之前被阻止并在春季被促进。 通过长时间的冷处理（如冬季）促进开花被称为春化。 对模式植物拟南芥春化过程的研究取得了重要进展。 在拟南芥中，春化作用是由两个基因的相互作用引起的，即阻断开花的FLC基因座C（FLC）和高水平FLC表达所需的FRI基因座A（FRI）。 寒冷导致FLC基因表达的表观遗传抑制，可能是在通过组蛋白乙酰化的染色质修饰水平上。 为了剖析FLC和FRI之间的调节相互作用，进行了详尽的突变体筛选。 该筛选导致分离FRI上调FLC所需的基因（称为FS基因）。 本提案的目的是表征FS基因在开花时间调节中的作用，使用遗传学，分子遗传学和生物化学方法。 这些研究将主要涉及：1）双突变分析，以表征各种FS基因之间的遗传关系; 2）酵母双筛选，以确定各种FS蛋白之间的相互作用;和3）微阵列分析，以分离FS基因产物的下游靶点。 更广泛的影响：由于通过染色质修饰的基因表达的变化已经在广泛的真核生物中被证明，包括酵母，果蝇，C。线虫和人类，这项研究很有可能提供具有广泛科学意义的新知识。 这项工作也有潜在的农业应用，因为大多数作物品种是两年生的，操纵其开花时间的能力可能为作物改良提供途径。 在人力资源方面，这项研究将为本科生、研究生和博士后研究员提供肥沃的培训基地。 还将为遗传学本科生和广大公众开发植物发育教育模块。