Salinity Is an Agent of Divergent Selection Driving Local Adaptation of Arabidopsis to Coastal Habitats
Salinity Is an Agent of Divergent Selection Driving Local Adaptation of Arabidopsis to Coastal Habitats
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DOI：
10.1104/pp.15.00427
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发表时间：
2015-07-01
期刊：
影响因子：
7.4
通讯作者：
Salt, David E.
中科院分区：
文献类型：
--
作者：
Busoms, Silvia;Teres, Joana;Salt, David E.
了解植物适应性进化的分子机制有助于深入了解驱动适应性的选择力量和具有农业价值的适应性性状的遗传基础。拟南芥(Arabitopsis Thaliana)的基因组资源使其非常适合于适应过程的快速分子解剖。虽然在拟南芥中已经确定了许多潜在的适应基因座，但不同的选择和迁移(这两个方面都是局部适应过程的重要方面)对拟南芥的影响还不是很清楚。在这里，我们使用一个多年的基于田间的相互移植实验来检测当地的拟南芥种群，这些种群由多个适应于西班牙东北部海岸和邻近内陆栖息地的小植物林(DEME)组成。我们确定了来自这些不同生境的植物在内陆和沿海共同花园中共同生长时以及在受控条件下从沿海和内陆遗址挖掘的土壤中的适合性权衡。当生长在高盐度下时，来自沿海生境的植物也比来自内陆的植物表现得更好，这表明当地对土壤盐分的适应。钠对植物是有毒的，我们发现在海岸采集的土壤和植物中，钠的浓度会升高。我们的结论是，我们观察到的邻近沿海和内陆种群之间的局部适应是由沿海和内陆土壤之间的盐分差异驱动的持续分化选择造成的。
Understanding the molecular mechanism of adaptive evolution in plants provides insights into the selective forces driving adaptation and the genetic basis of adaptive traits with agricultural value. The genomic resources available for Arabidopsis (Arabidopsis thaliana) make it well suited to the rapid molecular dissection of adaptive processes. Although numerous potentially adaptive loci have been identified in Arabidopsis, the consequences of divergent selection and migration (both important aspects of the process of local adaptation) for Arabidopsis are not well understood. Here, we use a multiyear field-based reciprocal transplant experiment to detect local populations of Arabidopsis composed of multiple small stands of plants (demes) that are locally adapted to the coast and adjacent inland habitats in northeastern Spain. We identify fitness tradeoffs between plants from these different habitats when grown together in inland and coastal common gardens and also, under controlled conditions in soil excavated from coastal and inland sites. Plants from the coastal habitat also outperform those from inland when grown under high salinity, indicating local adaptation to soil salinity. Sodium can be toxic to plants, and we find its concentration to be elevated in soil and plants sampled at the coast. We conclude that the local adaptation that we observe between adjacent coastal and inland populations is caused by ongoing divergent selection driven by the differential salinity between coastal and inland soils.