Department of Biochemistry, Max-Planck Institute for Chemical Ecology, Jena, Germany.
Institute of Plant Biology and Biotechnology, University of Münster, Münster, Germany.
Proc Biol Sci. 2021 Jul 28;288(1955):20211269. doi: 10.1098/rspb.2021.1269. Epub 2021 Jul 21.
Although non-genetic inheritance is thought to play an important role in plant ecology and evolution, evidence for adaptive transgenerational plasticity is scarce. Here, we investigated the consequences of copper excess on offspring defences and fitness under recurring stress in the duckweed across multiple asexual generations Growing large monoclonal populations (greater than 10 000 individuals) for 30 generations under copper excess had negative fitness effects after short and no fitness effect after prolonged growth under recurring stress. These time-dependent growth rates were likely influenced by environment-induced transgenerational responses, as propagating plants as single descendants for 2 to 10 generations under copper excess had positive, negative or neutral effects on offspring fitness depending on the interval between initial and recurring stress (5 to 15 generations). Fitness benefits under recurring stress were independent of flavonoid accumulations, which in turn were associated with altered plant copper concentrations. Copper excess modified offspring fitness under recurring stress in a genotype-specific manner, and increasing the interval between initial and recurring stress reversed these genotype-specific fitness effects. Taken together, these data demonstrate time- and genotype-dependent adaptive and non-adaptive transgenerational responses under recurring stress, which suggests that non-genetic inheritance alters the evolutionary trajectory of clonal plant lineages in fluctuating environments.
虽然非遗传继承被认为在植物生态学和进化中起着重要作用，但适应性跨代可塑性的证据很少。在这里，我们研究了在多个无性世代的浮萍中，铜过量对后代防御和适应反复胁迫的影响。在铜过量条件下生长 30 代后，大量单克隆种群（大于 10000 个个体）的生长对短期适应度有负面影响，但对长期适应度没有影响。这些随时间变化的生长率可能受到环境诱导的跨代反应的影响，因为在铜过量条件下，将植物作为单个后代繁殖 2 到 10 代，对后代适应度的影响取决于初始和反复胁迫之间的间隔（5 到 15 代）。反复胁迫下的适应度优势与类黄酮的积累无关，而类黄酮的积累又与植物铜浓度的改变有关。铜过量以特定基因型的方式改变了反复胁迫下后代的适应度，增加初始和反复胁迫之间的间隔会逆转这些特定基因型的适应度效应。总之，这些数据表明，在反复胁迫下存在时间和基因型依赖性的适应性和非适应性跨代反应，这表明非遗传继承会改变在波动环境中克隆植物谱系的进化轨迹。
