LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France.
Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Naples, Italy.
Mol Biol Evol. 2019 Jul 1;36(7):1442-1456. doi: 10.1093/molbev/msz078.
Despite the importance of plant-plant interactions on plant community dynamics and crop yield, our understanding of the adaptive genetics underlying these interactions is still limited and deserves to be investigated in the context of complex and diffuse interactions occurring in plant assemblages. Here, based on 145 natural populations of Arabidopsis thaliana located in south-west of France and characterized for plant communities, we conducted a Genome-Environment Association analysis to finely map adaptive genomic regions of A. thaliana associated with plant community descriptors. To control for correlated abiotic environment effects, we also characterized the populations for a set of biologically meaningful climate and soil variables. A nonnegligible fraction of top single nucleotide polymorphisms was associated with both plant community descriptors and abiotic variables, highlighting the importance of considering the actual abiotic drivers of plant communities to disentangle genetic variants for biotic adaptation from genetic variants for abiotic adaptation. The adaptive loci associated with species abundance were highly dependent on the identity of the neighboring species suggesting a high degree of biotic specialization of A. thaliana to members of its plant interaction network. Moreover, the identification of adaptive loci associated with α-diversity and composition of plant communities supports the ability of A. thaliana to interact simultaneously with multiple plant neighbors, which in turn can help to understand the role of community-wide selection. Altogether, our study highlights that dissecting the genetic basis underlying plant-plant interactions at a regional scale while controlling for abiotic confounding factors can help understanding the adaptive mechanisms modulating natural plant assemblages.
尽管植物-植物相互作用对植物群落动态和作物产量很重要，但我们对这些相互作用的适应性遗传基础的理解仍然有限，值得在复杂和分散的植物组合中发生的相互作用的背景下进行研究。在这里，我们基于位于法国西南部的 145 个自然拟南芥种群，并对植物群落进行了特征描述，进行了基因组-环境关联分析，以精细绘制与植物群落描述符相关的拟南芥适应性基因组区域。为了控制相关的非生物环境效应，我们还对种群进行了一系列有意义的气候和土壤变量的特征描述。相当一部分的顶级单核苷酸多态性与植物群落描述符和非生物变量都有关联，这突出了考虑实际的植物群落非生物驱动因素对于从非生物适应的遗传变异中分离出生物适应的遗传变异的重要性。与物种丰度相关的适应性基因座高度依赖于相邻物种的身份，这表明拟南芥对其植物相互作用网络成员的生物特异性程度很高。此外，与植物群落多样性和组成相关的适应性基因座的鉴定支持了拟南芥同时与多个植物邻居相互作用的能力，这反过来又有助于理解全社区选择的作用。总之，我们的研究强调，在控制非生物混杂因素的情况下，在区域尺度上剖析植物-植物相互作用的遗传基础，可以帮助理解调节自然植物组合的适应性机制。
