Rapid changes in the concentration of atmospheric carbon dioxide, a key driver of global climate change, have been shown to affect ecologically important traits in plants. Characterizing the effects of novel genetic variation on quantitative variation, phenotypic integration (multivariate associations among traits), and plasticity to elevated carbon dioxide can shed light on short-term plant responses to climate change. Here we explored univariate and multivariate responses to elevated carbon dioxide among four recombinant inbred populations of Arabidopsis thaliana established from genetically divergent ecotypes crossed to a common genetic background. We found significant genetic variation in all traits, but no genetic variation in phenotypic plasticity (i.e., genotype by environment interactions) in any trait among recombinant inbred lines. Significant cross-environment correlation in fitness values showed similar patterns of selection between ambient and elevated carbon dioxide treatments. Our data suggest that outcrossing among A. thaliana ecotypes increases genetic variation in functional traits, but makes little or no contribution to genotype by environment interactions and patterns of phenotypic integration. However, multivariate analyses revealed shifts in patterns of phenotypic integration in response to elevated carbon dioxide. We conclude that multivariate plasticity will likely play an important role in shaping short-term responses to future carbon dioxide conditions in natural populations of A. thaliana.

大气中二氧化碳浓度的快速变化是全球气候变化的主要驱动力，已显示出对植物生态学重要特征的影响。表征新的遗传变异对数量变异，表型整合（性状之间的多变量关联）以及对二氧化碳含量升高的可塑性的影响，可以为植物对气候变化的短期响应提供启示。在这里，我们探讨了拟南芥的四个重组近交种群中二氧化碳升高的单变量和多变量响应。从遗传上不同的生态型建立起来，并跨越了共同的遗传背景。我们发现所有性状的显着遗传变异，但在重组自交系中的任何性状的表型可塑性（即，环境相互作用的基因型）中均未发现遗传变异。适应度值之间的显着跨环境相关性表明，在环境二氧化碳处理和升高的二氧化碳处理之间的选择模式相似。我们的数据表明拟南芥中的异源杂交生态型增加了功能性状的遗传变异，但由于环境相互作用和表型整合模式而对基因型的贡献很小或没有贡献。然而，多变量分析显示，表型整合的模式随着二氧化碳浓度的升高而发生了变化。我们得出结论，多元可塑性可能会在拟南芥自然种群对未来二氧化碳状况的短期反应形成中起重要作用。