Phenological and fitness responses to climate warming depend upon genotype and competitive neighbourhood in Arabidopsis thaliana
Phenological and fitness responses to climate warming depend upon genotype and competitive neighbourhood in Arabidopsis thaliana
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DOI：
10.1111/1365-2435.13262
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发表时间：
2019-02-01
影响因子：
5.2
通讯作者：
Schmitt, Johanna
中科院分区：
文献类型：
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作者：
Taylor, Mark A.;Cooper, Martha D.;Schmitt, Johanna
众所周知，气候变化期间温度升高会改变不同植物类群的物候，但对这些变化的进化结果知之甚少。此外，植物的温度感应途径是已知的竞争感应途径相互作用，但仍然很少有实验证据表明，在现实的竞争环境中，不同的基因型在温度响应反应变暖。我们比较了开花时间和健身的反应升温和竞争的近等基因系（NILs）的拟南芥超亲分离的温度敏感和温度不敏感的等位基因的主要影响开花时间基因。我们生长的焦点植物的每一个基因型在种内和种间的竞争，在当代和温暖的条件下，在夏季和秋季的每日温度分布对比的四个治疗。我们测量了物候和健身的焦点植物量化塑料响应季节，温度和竞争，这些响应开花时间基因型的依赖性。温度不敏感的近等基因系是组成性早开花和不太适合，除了在未来的夏季气候中，其适合度高于晚开花，温度敏感的近等基因系在低竞争。晚开花的近等基因系表现出加速开花，以应对基因型内竞争和温度升高，在夏季，但延迟开花的秋天。然而，它的健身下降，在这两个季节的温度上升，并在秋季减少竞争的边际健身增益在未来减少。温度响应基因的功能等位基因是塑料对季节、变暖和竞争的反应所必需的。然而，塑料基因型并不是最适合在每一个实验条件下，成为低于温度渠化基因型在暖夏处理。气候变化通常被预测会对植物种群产生有害影响，我们的研究结果显示了温度升高如何通过基因型依赖的物候来降低适应性。此外，可塑性不一定是适应迅速变化的环境，因为一个非塑料基因型被证明比塑料基因型在气候变暖的处理。
Increasing temperatures during climate change are known to alter the phenology across diverse plant taxa, but the evolutionary outcomes of these shifts are poorly understood. Moreover, plant temperature-sensing pathways are known to interact with competition-sensing pathways, yet there remains little experimental evidence for how genotypes varying in temperature responsiveness react to warming in realistic competitive settings. We compared flowering time and fitness responses to warming and competition for two near-isogenic lines (NILs) of Arabidopsis thaliana transgressively segregating temperature-sensitive and temperature-insensitive alleles for major-effect flowering time genes. We grew focal plants of each genotype in intraspecific and interspecific competition in four treatments contrasting daily temperature profiles in summer and fall under contemporary and warmed conditions. We measured phenology and fitness of focal plants to quantify plastic responses to season, temperature and competition and the dependence of these responses on flowering time genotype. The temperature-insensitive NIL was constitutively early flowering and less fit, except in a future-summer climate in which its fitness was higher than the later flowering, temperature-sensitive NIL in low competition. The late-flowering NIL showed accelerated flowering in response to intragenotypic competition and to increased temperature in the summer but delayed flowering in the fall. However, its fitness fell with rising temperatures in both seasons, and in the fall its marginal fitness gain from decreasing competition was diminished in the future. Functional alleles at temperature-responsive genes were necessary for plastic responses to season, warming and competition. However, the plastic genotype was not the most fit in every experimental condition, becoming less fit than the temperature-canalized genotype in the warm summer treatment. Climate change is often predicted to have deleterious effects on plant populations, and our results show how increased temperatures can act through genotype-dependent phenology to decrease fitness. Furthermore, plasticity is not necessarily adaptive in rapidly changing environments since a nonplastic genotype proved fitter than a plastic genotype in a warming climate treatment.