Co-evolution of Shade Avoidance and Response to Photoperiod in Arabidopsis Thaliana

本项目以拟南芥（Arabidopsis thaliana）为研究对象，研究植物对日照长度和光谱光质量两个环境因子的响应演化。问题是要了解植物如何整合不同的环境信号，以及它们是否通过调整自己的生活史来适当地“回应”，以最大限度地提高自己的适应性。选择昼长和光质量是因为它们是植物用来评估环境条件的重要线索。白昼长度是季节变化的一个指标，植物可以利用它来确定春季或夏季（取决于纬度）的最佳开花时间。光质量（以红光和远红光之间的比率来衡量）已被证明是周围植被密度的一个指标，也可能是争夺光的强度的一个指标。这项研究将包括一个野外部分，在此期间，植物将沿着从南欧到北欧（拟南芥的自然栖息地）的纬度梯度从其自然环境中进行研究和收集。然后将进行分子分析，以估计收集到的种群之间的关系有多密切。最后，将进行一系列温室实验，以测量植物对不同日照长度和光照质量组合的反应。这种研究对于了解自然选择是否以及如何使植物的外观和生活史与环境带来的挑战相匹配非常重要。由于拟南芥已经从分子角度进行了深入研究，因此可以将其生态学和进化的知识与已经发表的研究相结合，以更好地理解整个生物体的生物学。由于这种植物也是经济上重要的物种如西兰花、花椰菜和芥菜的近亲，通过研究拟南芥获得的知识可能对作物改良有直接的应用。

Pigliucci0089493This project aims at studying the evolution of plants' responses to two environmental factors, daylength and spectral light quality, using the weedy species Arabidopsis thaliana. The problem is to understand how plants integrate different environmental signals and if they "respond" appropriately by adjusting their life history to maximize their fitness. Daylength and light quality were chosen because they are important cues the plant uses to assess environmental conditions. Daylength is an indicator of seasonal changes, and can be used by plants to determine the optimal period of flowering during the spring or summer (depending on the latitude). Light quality (measured as the ratio between red and far red light) has been demonstrated to be an indicator of the density of the surrounding vegetation, and presumably the intensity of competition for light. This research will include a field component during which plants will be studied and collected from their natural environment along a latitudinal gradient from southern to northern Europe (the natural habitat for Arabidopsis). A molecular analysis will then be carried out to estimate how closely related the collected populations are to each other. Finally, a series of greenhouse experiments will be conducted to measure how the plants react to different combinations of daylength and light quality.This kind of study is important to understand if and how natural selection can match a plant's appearance and life history to the challenges posed by the environment. Because Arabidopsis has been intensively studied from a molecular perspective, knowledge of its ecology and evolution can be integrated with already published studies to achieve a better comprehension of the biology of the whole organism. Since this plant is also a close relative of economically important species such as broccoli, cauliflower and mustard, the knowledge gained by studying Arabidopsis may have direct applications for crop improvement.