Abstract Studies on water deficit follow methodologies with short recovery intervals, which makes it difficult to determine whether a long-lasting memory is imprinted. There is a paucity of information on the dehydration level and time needed to form memory. This study aimed to evaluate whether rapid dehydration in the early stages of sorghum life induces changes in the epigenetic mechanisms, antioxidant activities, photosynthesis, total stomatal density, dry mass and leaf area of this species subjected to water deficit in a later growth stage. Four treatments were assessed: irrigated plants, plants subjected to rapid dehydration for 2:30 h at the beginning of their life, plants subjected to water deficit by withholding irrigation in adulthood, and plants subjected to rapid dehydration with a subsequent water deficit in adulthood. The antioxidant and photosynthesis results showed that the latter treatment was the more tolerant to water deficit and also led to a reduction in total stomatal density to avoid water loss; however, under this treatment shoot dry mass decreased. Moreover, plants subjected to two water stress events presented high occurrence and maintenance of the epigenetic memory marker H3K4me3. Therefore, rapid stimulation of early-life dehydration can induce long-term water deficit memory.

中文翻译：

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快速脱水诱导高粱幼苗长期缺水记忆：优势和后果

摘要 缺水研究遵循的方法是恢复间隔较短，这使得很难确定是否留下了持久的记忆。关于脱水程度和形成记忆所需时间的信息很少。本研究旨在评估高粱生命早期阶段的快速脱水是否会导致该物种在生长后期缺水的表观遗传机制、抗氧化活性、光合作用、总气孔密度、干重和叶面积发生变化。评估了四种处理方式：灌溉植物、生命初期经历 2:30 小时快速脱水的植物、成年期因停止灌溉而缺水的植物以及经历快速脱水并随后在成年期缺水的植物。抗氧化和光合作用结果表明，后一种处理对水分亏缺的耐受性更强，同时也导致总气孔密度降低以避免水分流失；然而，在这种处理下，芽干质量下降。此外，遭受两次水分胁迫的植物表现出表观遗传记忆标记 H3K4me3 的高发生率和维持率。因此，对生命早期脱水的快速刺激可诱发长期缺水记忆。