Seedling response to water stress in valley oak (Quercus lobata) is shaped by different gene networks across populations
Seedling response to water stress in valley oak (Quercus lobata) is shaped by different gene networks across populations
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DOI：
10.1111/mec.15289
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发表时间：
2019-11-19
影响因子：
4.9
通讯作者：
Sork, Victoria L.
中科院分区：
文献类型：
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作者：
Mead, Alayna;Penaloza Ramirez, Juan;Sork, Victoria L.
干旱是植物的主要胁迫，对使植物在干燥环境中生长和生存的性状产生强大的选择压力。许多干旱反应是物种范围内保守的反应，而其他反应则因分布在异质环境中的种群而异。我们通过测量 93 个个体的生态生理特征和 42 个个体的基因表达 (RNA-seq)，测试了从不同气候中采集的广泛分布的加州山谷橡树 (Quercus lobata) 的 6 个种群，相对于共同环境中浇水良好的对照组，它们对土壤干燥的反应有何不同。在土壤干燥过程中，种群对膨压损失点的调整没有差异，这表明了物种范围内的普遍反应。差异表达分析确定了 689 个对不同人群的治疗具有共同反应的基因和 470 个具有人群特异性反应的基因。加权基因共表达网络分析（WGCNA）识别了具有相似表达模式且可以一起调节的基因组（基因模块）。几个基因模块对不同人群的水分胁迫有不同的反应，这表明基因网络调控存在区域差异。年平均气温高的地区的种群对所施加的水分胁迫的反应具有显着更大的基因模块表达变化，表明这些种群可能在当地适应了干旱的反应。我们认为，山谷橡树种群之间的这种差异提供了一种对加利福尼亚州日益频繁和严重的干旱进行差异耐受的机制。
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 with similar expression patterns that may be regulated together (gene modules). Several gene modules responded differently to water stress among populations, suggesting regional differences in gene network regulation. Populations from sites with a high mean annual temperature responded to the imposed water stress with significantly greater changes in gene module expression, indicating that these populations may be locally adapted to respond to drought. We propose that this variation among valley oak populations provides a mechanism for differential tolerance to the increasingly frequent and severe droughts in California.