Seedling response to water stress in valley oak (Quercus lobata) is shaped by different gene networks across populations

Drought is a major stress for plants, creating a strong selection pressure for traits that enable plant growth and survival in dry environments. Many drought responses are conserved species-wide responses while others vary among populations distributed across heterogeneous environments. We tested how six populations of the widely-distributed California valley oak (Quercus lobata) sampled from contrasting climates would differ in their response to soil drying relative to well-watered controls in a common environment by measuring ecophysiological traits in 93 individuals and gene expression (RNA-seq) in 42 individuals. Populations did not differ in their adjustment of turgor loss point during soil-drying, suggesting a generalized species-wide response. Differential expression analysis identified 689 genes with a common response to treatment across populations, and 470 genes with population-specific responses. Weighted gene co-expression network analysis (WGCNA) identified groups of genes ...

干旱是植物面临的主要胁迫之一，为适应干旱环境下生长与存活的相关性状带来了极强的选择压力。许多干旱响应在物种水平上具有保守性，而另一些响应则在分布于异质环境的不同种群间存在差异。本研究以6个广泛分布的加州河谷栎（Quercus lobata）种群为研究对象，这些种群采自气候差异显著的生境。研究在统一可控环境中设置土壤干旱处理与正常浇水对照组，通过测定93个个体的生态生理性状以及42个个体的基因表达（RNA-seq），探究不同种群在土壤干旱响应模式上的差异。各种群在土壤干旱过程中的膨压损失点调控并无显著差异，这表明该响应为物种水平的一般性保守响应。差异表达分析共鉴定出689个在所有种群中对处理具有共同响应的基因，以及470个具有种群特异性响应的基因。加权基因共表达网络分析（WGCNA）鉴定出了若干基因模块……