Data from: Patterns of phenotypic plasticity and local adaptation in the wide elevation range of the alpine plant Arabis alpina

Local adaptation and phenotypic plasticity are two important characteristics of alpine plants to overcome the threats caused by global changes. Among alpine species, Arabis alpina is characterised by an unusually wide altitudinal amplitude, ranging from 800 to 3,100 m of elevation in the French Alps. Two non‐exclusive hypotheses can explain the presence of A. alpina across this broad ecological gradient: adaptive phenotypic plasticity or local adaptation, making this species especially useful to better understand these phenomena in alpine plant species. We carried out common garden experiments at two different elevations with maternal progenies from six sites that differed in altitude. We showed that (1) key phenotypic traits (morphotype, total fruit length, growth, height) display significant signs of local adaptation, (2) most traits studied are characterised by a high phenotypic plasticity between the two experimental gardens and (3) the two populations from the highest elevations lacked morphological plasticity compared to the other populations. By combining two genome scan approaches (detection of selection and association methods), we isolated a candidate gene (Sucrose‐Phosphate Synthase 1). This gene was associated with height and local average temperature in our studied populations, consistent with previous studies on this gene in Arabidopsis thaliana. Synthesis. Given the nature of the traits involved in the detected pattern of local adaptation and the relative lack of plasticity of the two most extreme populations, our findings are consistent with a scenario of a locally adaptive stress response syndrome in high elevation populations. Due to a reduced phenotypic plasticity, an overall low intra‐population genetic diversity of the adaptive traits and weak gene flow, populations of high altitude might have difficulties to cope with, e.g. a rise of temperature.本地适应（local adaptation）与表型可塑性（phenotypic plasticity）是高山植物应对全球变化所带来威胁的两类重要适应性特征。在高山植物类群中，高山南芥（Arabis alpina）具有异常宽泛的海拔分布幅度，在法国阿尔卑斯山区其分布海拔范围可达800至3100米。有两个非互斥假说可解释高山南芥在该宽泛生态梯度上的分布：适应性表型可塑性或本地适应，这使得该物种成为研究高山植物此类适应性现象的理想材料。 本研究针对6个不同海拔来源的母本后代，在两个不同海拔高度开展了同质园（common garden）实验。研究结果显示：(1) 核心表型性状（形态型、果实总长度、生长速率、株高）均表现出显著的本地适应特征；(2) 绝大多数被测性状在两个实验同质园之间表现出较高的表型可塑性；(3) 相较于其他种群，两个高海拔种群的形态可塑性显著缺失。 本研究结合两种基因组扫描方法（选择检测与关联分析方法），筛选得到一个候选基因（candidate gene）——蔗糖磷酸合成酶1（Sucrose-Phosphate Synthase 1）。在本研究的种群中，该基因与株高及局地平均温度显著相关，这与此前在拟南芥（Arabidopsis thaliana）中针对该基因开展的研究结果一致。 综合分析表明，结合本次研究中检测到的本地适应性状特征，以及两个极端高海拔种群相对匮乏的可塑性，本研究结果支持高海拔种群存在本地适应性胁迫响应综合征的假说。由于表型可塑性降低、适应性性状的种群内遗传多样性整体偏低，且基因流较弱，高海拔种群可能难以应对诸如气温升高等环境变化。