Functional analysis of multi-gene complexes regulating photoperiod-dependent flowering time

项目名称：“调节光周期依赖性开花时间的多基因复合物的功能分析”，即使是最不经意的观察者，也知道植物的开花（繁殖）与季节有关。这并非偶然——就像所有成功的生物一样，植物在其原生环境的独特问题下进化，并发展出在最佳条件下生长和繁殖的能力。由于农业生产力在很大程度上取决于发育事件的时间，发现植物如何利用环境的变化来决定何时开始开花是植物生物学中的一个重要问题。在温带气候中，如美国，许多环境变量全年都在变化。由于白昼长度的变化（或“光周期”）在不同年份之间基本上是相同的，许多植物将其作为准确的信号，在正确的时间触发开花。尽管科学家们开始揭示植物决定光周期的潜在分子机制，但仍有很多东西需要学习。这个项目的重点是研究几个新的基因，这些基因对响应变化的光周期而适当的开花时间是必要的。这些基因突变的植物失去了正确利用日照长度作为开花线索的能力；相反，它们的开花时间比正常晚了几周甚至几个月。虽然这些基因的身份是已知的，但不知道这些基因是如何帮助植物在正确的时间开花的。这些相同的基因参与了第二次发育转变——从种子休眠到发芽的转变。利用遗传学、分子生物学和生物化学的组合工具，该项目将解决1)这些基因如何在植物细胞中发挥作用来开启开花，以及2)它们如何同时控制种子发芽。由于开花时间和种子休眠都是重要的农业性状，了解这些过程如何交叉对提高未来作物性能至关重要。

PI: Ben Ford Holt III,Proposal Number: IOS-0920258Project Title: "Functional analysis of multi-gene complexes regulating photoperiod-dependent flowering time" For even the most casual observer, it is well known that plant flowering (reproduction) is coupled to the seasons. This is no accident - like all successful organisms, plants evolved with the unique problems of their native environments and have developed the ability to grow and reproduce under optimal conditions. Because agricultural productivity depends heavily on the timing of developmental events, discovering how plants use changes in their environment to determine when to begin flowering is an important question in plant biology. In temperate climates, such as the United States, many environmental variables change throughout the year. As changes in day length (or "photoperiod") are essentially identical between years, many plants use this as an accurate signal to trigger flowering at the correct time. Although scientists are beginning to unravel the underlying molecular mechanisms used by plants to determine photoperiod, there is still much to learn. This project is focused on several new genes that are necessary for the appropriate timing of flowering in response to changing photoperiod. Plants with mutant versions of these genes lose the ability to properly use day length as a cue to flower; instead, they flower several weeks or even months later than normal. Although the identity of these genes is known, it is not known how theses genes help plants flower at the right time. These same genes are involved in a second developmental transition - the shift from seed dormancy to germination. Using the combined tools of genetics, molecular biology, and biochemistry, this project will address 1) how these genes are acting to turn on flowering in the plant cell, and 2) how they are functioning to simultaneously control seed germination. Because both flowering time and seed dormancy are important agricultural traits, understanding how these processes intersect is essential to enhancing future crop performance.