Response to Light Quality and Photoperiod in Arabidopsis: Plasticity and Pleiotropy

拟南芥对光质量和光周期的响应：可塑性和多效性

• 批准号: 9707552
• 负责人: Massimo Pigliucci
• 金额: $ 12.7万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9707552&HistoricalAwards=false
• 关键词: Response; Light; Quality; Photoperiod; Arabidopsis

Pigliucci 9707552 Molecular geneticists and physiologists working with the model system Arabidopsis thaliana have achieved a detailed mechanistic understanding of two distinct forms of phenotypic plasticity: the response to light quality and the response to photoperiod. These analyses have clearly established that there is extensive overlap among the genes that regulate these two forms of plasticity, raising questions about the evolutionary origins and ecological implications of pleiotropy and genetic redundancy. The PIs' understanding of these genetic details allows us to address a complex question: how do plants integrate a suite of cues that provide information about different aspects of multifactor selective environments? For annual plants, light quality serves as a specific and reliable cue for present and imminent competition for light, because encroaching competitors alter light quality (i.e., the ratio of red to far-red light - R:FR). Similarly, in the temperate regions where A. thaliana grows, the length of the photoperiod is an indicator of seasonality. Can natural populations of A. thaliana respond to selection on the ability to sense and respond to light quality cues? How strong is the relationship, if any, between the R:FR-mediatedplasticity syndrome, andphotoperiod-mediated plasticity? The PIs will propose a short-term selection experiment with replicated selection and control lines. The PIs will work with a large natural population already under intensive study in East Tennessee. We will select directly on the R:FR-mediated plasticity of flowering time. While assessing the response to this direct selection, we will also examine two forms of indirect response. First, was there a response in the R:FR-mediated plasticity of other traits? Second, was there a response in the photoperiod-mediated plasticity (i.e., a different cue) of the same trait, flowering time? The PIs' plan to address the interaction among traits and be tween R:FR- and photoperiodmediated plasticity in a series of mutant lines. These mutants lack specific photoreceptor genes that affect a suite of traits, including reproductive fitness. Furthermore, in these mutant lines and their associated wild types, normal and altered patterns of plasticity occur in the same genetic background. Thus, it is possible to make strong inferences about how a gene (or genes) controlling plasticity affects the whole organism, including its performance or fitness (pleiotropy).

皮柳奇9707552 研究模式系统拟南芥的分子遗传学家和生理学家已经对两种不同形式的表型可塑性取得了详细的机制理解：对光质量的反应和对光周期的反应。这些分析清楚地表明，在调节这两种形式的可塑性的基因之间存在广泛的重叠，这引发了关于多效性和遗传冗余的进化起源和生态学意义的问题。PI对这些遗传细节的理解使我们能够解决一个复杂的问题：植物如何整合一套线索，提供有关多因素选择环境不同方面的信息？ 对于一年生植物，光质量作为当前和即将到来的光竞争的具体和可靠的线索，因为侵入的竞争者改变光质量（即，红光与远红光的比率- R：FR）。同样，在温带地区，A.在生长过程中，光周期的长短是季节性的一个指标。A. thaliana响应选择的能力，感觉和响应光质量线索？R：FR介导的可塑性综合征和光周期介导的可塑性之间的关系有多强？ PI将提出一个短期选择实验，重复选择和控制线。PI将与田纳西州东部已经进行深入研究的大量自然种群合作。我们将直接选择对R：FR介导的开花时间的可塑性。在评估对这种直接选择的反应时，我们还将研究两种形式的间接反应。 首先，是否有一个反应，在R：FR介导的可塑性的其他性状？第二，在光周期介导的可塑性中是否存在响应（即，一个不同的线索）的同一性状，开花时间？ PI计划在一系列突变系中解决性状之间的相互作用以及R：FR-和光周期介导的可塑性之间的相互作用。这些突变体缺乏影响一系列特征的特定感光基因，包括生殖适应性。 此外，在这些突变株系及其相关的野生型中，正常和改变的可塑性模式发生在相同的遗传背景中。因此，我们有可能对控制可塑性的一个（或多个）基因如何影响整个生物体做出强有力的推论，包括其性能或适应性（多效性）。