Subrahmaniam Harihar Jaishree, Picó F Xavier, Bataillon Thomas, Salomonsen Camilla Lind, Glasius Marianne, Ehlers Bodil K
Department of Ecoscience, Aarhus University, Aarhus C, 8000, Denmark.
Institut für Pflanzenwissenschaften und Mikrobiologie, Universität Hamburg, Hamburg, 22609, Germany.
New Phytol. 2025 Feb;245(4):1437-1449. doi: 10.1111/nph.20314. Epub 2024 Dec 10.
Plant root exudates are involved in nutrient acquisition, microbial partnerships, and inter-organism signaling. Yet, little is known about the genetic and environmental drivers of root exudate variation at large geographical scales, which may help understand the evolutionary trajectories of plants in heterogeneous environments. We quantified natural variation in the chemical composition of Arabidopsis thaliana root exudates in 105 Iberian accessions. We identified up to 373 putative compounds using ultra-high-performance liquid chromatography coupled with mass spectrometry. We estimated the broad-sense heritability of compounds and conducted a genome-wide association (GWA) study. We associated variation in root exudates to variation in geographic, environmental, life history, and genetic attributes of Iberian accessions. Only 25 of 373 compounds exhibited broad-sense heritability values significantly different from zero. GWA analysis identified polymorphisms associated with 12 root exudate compounds and 26 known genes involved in metabolism, defense, signaling, and nutrient transport. The genetic structure influenced root exudate composition involving terpenoids. We detected five terpenoids related to plant defense significantly varying in mean abundances in two genetic clusters. Our study provides first insights into the extent of root exudate natural variation at a regional scale depicting a diversified evolutionary trajectory among A. thaliana genetic clusters chiefly mediated by terpenoid composition.
植物根系分泌物参与养分获取、微生物共生以及生物体间信号传导。然而，在大地理尺度上，关于根系分泌物变异的遗传和环境驱动因素我们知之甚少，而这些因素可能有助于理解植物在异质环境中的进化轨迹。我们对105个伊比利亚地区拟南芥种质的根系分泌物化学成分的自然变异进行了量化。我们使用超高效液相色谱与质谱联用技术鉴定出多达373种推定化合物。我们估计了这些化合物的广义遗传力，并进行了全基因组关联（GWA）研究。我们将根系分泌物的变异与伊比利亚种质的地理、环境、生活史和遗传属性的变异联系起来。373种化合物中只有25种的广义遗传力值显著不同于零。全基因组关联分析确定了与12种根系分泌物化合物以及26个参与代谢、防御、信号传导和养分运输的已知基因相关的多态性。遗传结构影响了涉及萜类化合物的根系分泌物组成。我们检测到与植物防御相关的5种萜类化合物在两个遗传簇中的平均丰度存在显著差异。我们的研究首次揭示了区域尺度上根系分泌物自然变异的程度，描绘了拟南芥遗传簇之间主要由萜类化合物组成介导的多样化进化轨迹。
