State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China.
Hubei Hongshan Laboratory, Wuhan, 430070, China.
New Phytol. 2022 Oct;236(2):385-398. doi: 10.1111/nph.18341. Epub 2022 Jul 13.
Genetic signature of climate adaptation has been widely recognized across the genome of many organisms; however, the eco-physiological basis for linking genomic polymorphisms with local adaptations remains largely unexplored. Using a panel of 218 world-wide Arabidopsis accessions, we characterized the natural variation in root suberization by quantifying 16 suberin monomers. We explored the associations between suberization traits and 126 climate variables. We conducted genome-wide association analysis and integrated previous genotype-environment association (GEA) to identify the genetic bases underlying suberization variation and their involvements in climate adaptation. Root suberin content displays extensive variation across Arabidopsis populations and significantly correlates with local moisture gradients and soil characteristics. Specifically, enhanced suberization is associated with drier environments, higher soil cation-exchange capacity, and lower soil pH; higher proportional levels of very-long-chain suberin is negatively correlated with moisture availability, lower soil gravel content, and higher soil silt fraction. We identified 94 putative causal loci and experimentally proved that GPAT6 is involved in C16 suberin biosynthesis. Highly significant associations between the putative genes and environmental variables were observed. Roots appear highly responsive to environmental heterogeneity via regulation of suberization, especially the suberin composition. The patterns of suberization-environment correlation and the suberin-related GEA fit the expectations of local adaptation for the polygenic suberization trait.
遗传适应的特征在许多生物的基因组中得到了广泛的认可；然而，将基因组多态性与局部适应性联系起来的生态生理基础在很大程度上仍未得到探索。利用 218 个来自世界各地的拟南芥品系，我们通过定量分析 16 种角质单体来表征根角质层的自然变异。我们探讨了角质层特性与 126 个气候变量之间的关联。我们进行了全基因组关联分析，并整合了先前的基因型-环境关联（GEA），以确定角质层变异的遗传基础及其在气候适应中的作用。拟南芥群体的根角质层含量表现出广泛的变异，与当地的水分梯度和土壤特性显著相关。具体而言，增强的角质层与较干燥的环境、较高的土壤阳离子交换能力和较低的土壤 pH 值有关；较高比例的超长链角质层与水分可用性呈负相关，与较低的土壤砾石含量和较高的土壤粉砂分数有关。我们鉴定了 94 个假定的因果基因座，并通过实验证明 GPAT6 参与了 C16 角质层的生物合成。在假定的基因和环境变量之间观察到高度显著的关联。根似乎通过角质层的调节对环境异质性高度敏感，特别是角质层的组成。角质层与环境相关的模式和与角质层相关的 GEA 符合多基因角质层性状的局部适应预期。
