Molecular mechanism and adaptive value of leaf shape plasticity in the genus Capsella.

植物作为固着生物，强烈地暴露在环境中，因此必须进化出复杂的机制来适应环境条件的发育和生理。由于气候在本质上是高度不可预测的，而且在天、月和年之间波动很大，因此这些适应需要是动态的和可塑性的。事实上，植物必须能够迅速感知它们的环境，并相应地优化它们的新陈代谢和生长，以便在这些条件下表现最佳。叶子是植物中最具可塑性的器官之一。它们的生物学功能迫使树叶在形成足够的表面积以优化气体交换和捕捉到的光量之间找到平衡，同时将它们在压力条件下的暴露降至最低。因此，叶片的最终大小和形状在很大程度上取决于生长条件。一个长期的观察是，叶片解剖的水平与温度呈负相关。然而，关于将温度信号整合到叶片发育中的分子机制，以及由此导致的叶片几何形状的变化如何有助于适合性，人们知之甚少。该项目的目的是利用我们最近在温度诱导的野菜属叶形可塑性遗传基础上的发现，来研究气候、叶表面积和植物整体适合度之间的分子和生态关系。在这个属中，环境温度的降低激活了降低复杂性3(RCO-3)基因的表达，这反过来又增加了叶片的解剖水平。本属的两个姊妹种之间的这个基因座的多态是叶形和RCO-3温度反应的自然差异的基础。RCO-3温度感知中的这种等位基因变异为剖析与温度诱导的叶形可塑性相关的分子机制和生态后果提供了独特的机会。

Plants as sessile organisms are strongly exposed to their environment and therefore had to evolve elaborate mechanisms to adapt their development and physiology to ambient conditions. Since climate is highly unpredictable in nature and fluctuates considerably over days, months and years, these adaptations need to be dynamic and plastic. Indeed, plants have to be able to rapidly sense their environment and optimise their metabolism and growth accordingly to best perform in those conditions. The leaf is one of the most plastic organs in plants. Their biological function obliges leaves to find a balance between developing a sufficient surface area to optimise gas exchange and the amount of light that can be captured, while minimizing their exposure to stressful conditions. As a result, the final size and shape of leaves are highly dependent on growing conditions. A long standing observation is that the level of leaf dissection negatively correlates with temperature. However, very little is known about the molecular mechanisms that integrate temperature signals into leaf development and how the resulting changes in leaf geometry may contribute to fitness. The proposed project aims to take advantage of our recent findings on the genetic basis of temperature-induced leaf shape plasticity in the genus Capsella to investigate the molecular and ecological relationship between climate, leaf surface area and overall plant fitness. In this genus, a decrease in ambient temperature activate the expression of the REDUCED COMPLEXITY 3 (RCO-3) gene, which in turn increase the dissection level of the leaves. Polymorphisms within this locus between two sister species of this genus underlie natural variation in leaf shape and RCO-3 temperature response. This allelic variation in RCO-3 temperature perception offers a unique opportunity to dissect the molecular mechanisms and ecological consequences associated with temperature-induced leaf shape plasticity.