Adaptive Transgenerational Plasticity in an Annual Plant: Grandparental and Parental Drought Stress Enhance Performance of Seedlings in Dry Soil
Adaptive Transgenerational Plasticity in an Annual Plant: Grandparental and Parental Drought Stress Enhance Performance of Seedlings in Dry Soil
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DOI：
10.1093/icb/ics041
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发表时间：
2012-07-01
影响因子：
2.6
通讯作者：
Riggs, Charlotte
中科院分区：
文献类型：
--
作者：
Herman, Jacob J.;Sultan, Sonia E.;Riggs, Charlotte
压力的父母（通常是母亲）环境可以显着影响后代的性状表达，在某些情况下，导致适应诱导压力的表型。这种跨代可塑性的生态和进化影响取决于其跨代的持久性和适应价值。很少有研究在一个给定的系统内检查跨代可塑性的两个方面。在这里，我们报告的结果，生长室研究的适应性跨世代可塑性在两代，使用广泛的一年生植物蓼persicaria作为一个自然进化的模型系统。我们在控制的干燥与潮湿的土壤环境中生长了五个近交蓼属遗传系两代，采用完全析因设计，在祖父母和父母环境的所有排列下产生每个遗传系的重复个体。然后，我们测量的影响，这些两代压力的历史上的特征关键功能在干燥的土壤中，在第三代（孙子）的幼苗后代提出的干燥处理。祖父母和父母的水分环境显着影响幼苗发育：幼苗干旱胁迫的祖父母或父母产生更长的根系，延伸更深，更快地进入干燥的土壤相比，相同的遗传线的祖父母和/或父母已充分浇水。有压力的个体的后代也比无压力的父母和祖父母的后代生长到更大的生物量。重要的是，干旱的影响在两代人的过程中是累积的：当祖父母和父母都受到干旱胁迫时，后代有最大的供应，发芽最早，并发育成最大的幼苗，具有最广泛的根系。沿着这些功能上适当的发展影响，幼苗产生后，前两个干旱胁迫代有显着更大的生存在非常干燥的土壤比幼苗没有干旱的历史。这些研究结果表明，祖父母和父母经历的自然资源压力的塑料反应可以“预适应”后代在相同的压力下运作的方式，可测量地影响实现健身。这些环境引起的，遗传的适应可能产生的影响进行了讨论，生态分布，持久性下的新的压力，在自然种群的进化。
Stressful parental (usually maternal) environments can dramatically influence expression of traits in offspring, in some cases resulting in phenotypes that are adaptive to the inducing stress. The ecological and evolutionary impact of such transgenerational plasticity depends on both its persistence across generations and its adaptive value. Few studies have examined both aspects of transgenerational plasticity within a given system. Here we report the results of a growth-chamber study of adaptive transgenerational plasticity across two generations, using the widespread annual plant Polygonum persicaria as a naturally evolved model system. We grew five inbred Polygonum genetic lines in controlled dry vs. moist soil environments for two generations in a fully factorial design, producing replicate individuals of each genetic line with all permutations of grandparental and parental environment. We then measured the effects of these two-generational stress histories on traits critical for functioning in dry soil, in a third (grandchild) generation of seedling offspring raised in the dry treatment. Both grandparental and parental moisture environment significantly influenced seedling development: seedlings of drought-stressed grandparents or parents produced longer root systems that extended deeper and faster into dry soil compared with seedlings of the same genetic lines whose grandparents and/or parents had been amply watered. Offspring of stressed individuals also grew to a greater biomass than offspring of nonstressed parents and grandparents. Importantly, the effects of drought were cumulative over the course of two generations: when both grandparents and parents were drought-stressed, offspring had the greatest provisioning, germinated earliest, and developed into the largest seedlings with the most extensive root systems. Along with these functionally appropriate developmental effects, seedlings produced after two previous drought-stressed generations had significantly greater survivorship in very dry soil than did seedlings with no history of drought. These findings show that plastic responses to naturalistic resource stresses experienced by grandparents and parents can "preadapt" offspring for functioning under the same stresses in ways that measurably influence realized fitness. Possible implications of these environmentally-induced, inherited adaptations are discussed with respect to ecological distribution, persistence under novel stresses, and evolution in natural populations.