Epigenetic diversity could play an important role in adaptive evolution of organisms, especially for plant species occurring in new and stressful environments. Thlaspi arvense (field pennycress), a valuable oilseed crop, is widespread in temperate regions of the northern hemisphere. In this study, we investigated the effect of salinity stress on the epigenetic variation of DNA methylation and epigenetic stress memory in pennycress using methylation‐sensitive amplification polymorphism (MSAP) markers. We examined how the status of DNA methylation changes across individuals in response to salinity stress and whether such an effect of maternal stress could be transferred to offspring for one or two generations in nonstressed environments. Our results based on 306 epiloci indicated no consistent change of DNA methylation status in specific epiloci across individuals within the same conditions. In contrast, we found that the epigenetic diversity at population level increased significantly in response to the stimulation of salinity stress; and this “stimulation effect” could be transferred partially in the form of stress memory to at least two generations of offspring in nonstressed environments. In addition, we observed a parallel change in functionally important traits, that is, phenotypic variation was significantly higher in plants grown under salinity stress compared with those of control groups. Taken together, our results provide novel clues for the increased spontaneous epimutation rate in response to stress in plants, of potential adaptive significance.

中文翻译：

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盐胁迫下盐胁迫对表观遗传多样性和瞬时表观遗传记忆的影响

表观遗传多样性可以在生物的适应性进化中发挥重要作用，特别是对于在新的和压力环境中发生的植物物种而言。黄las（田pen豆）是一种有价值的油料作物，在北半球的温带地区广泛分布。在这项研究中，我们使用甲基化敏感性扩增多态性（MSAP）标记研究了盐分胁迫对豆瓣DNA甲基化的表观遗传变异和表观遗传应力记忆的影响。我们研究了在盐胁迫下个体间DNA甲基化状态如何变化，以及在非胁迫环境下母体胁迫的这种影响是否可以传递给后代一到两代。我们基于306个Epiloci的结果表明，在相同条件下，个体中特定Epiloci的DNA甲基化状态没有一致的变化。相反，我们发现，在盐分胁迫的刺激下，种群水平的表观遗传多样性显着增加。这种“刺激效应”可以以压力记忆的形式部分转移到无压力环境中的至少两代后代中。此外，我们观察到功能重要性状的平行变化，即与对照组相比，盐分胁迫下生长的植物的表型变异明显更高。两者合计，我们的结果提供了新的线索，表明自发epi变率增加对植物胁迫的响应，具有潜在的适应性意义。我们观察到功能重要性状的平行变化，即在盐胁迫下生长的植物的表型变异明显高于对照组。两者合计，我们的结果提供了新的线索，表明自发epi变率增加对植物胁迫的响应，具有潜在的适应性意义。我们观察到功能重要性状的平行变化，即在盐胁迫下生长的植物的表型变异明显高于对照组。两者合计，我们的结果提供了新的线索，表明自发epi变率增加对植物胁迫的响应，具有潜在的适应性意义。