Desiccation tolerance (DT) of seeds, one of the plant's environmental adaptation mechanisms, allows them to survive as seeds in a quiescent state under extremely water-deficient conditions during the plant's life cycle, followed by seed germination and seedling establishment under favourable water conditions. The seed-DT is lost after radicle emergence; however, there is a developmental period called the ‘DT window’ during which the germinating seeds can re-induce DT following a cue from their ambient low water potential (i.e. mild osmotic stress). The DT re-inducibility within the DT window has been used as a model biosystem for understanding molecular mechanisms that activate/supress DT in a number of plant species. However, the characteristics of the DT window for species particularly important to the agroindustry are still largely fragmented. Here, physiological analyses were performed, aiming to elucidate the properties of the DT window in tomato, a model species for Solanaceae, holding a key strategic position for the seed industry and commercial use around the world. We revealed that (i) the DT window of tomato seeds is closed when the developing radicle reaches about 4 mm after germination, (ii) the most effective ambient water potential to re-induce DT into seeds is about −1.5 MPa and (iii) there is organ specificity of DT re-induction with hypocotyls, showing a longer DT window than cotyledons and roots in post-germination seeds.

中文翻译：

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重新建立发芽番茄（Solanum lycopersicum）种子的干燥耐受性

种子的耐干燥性（DT）是植物的环境适应机制之一，使种子能够在植物生命周期中极度缺水的条件下以静止状态生存，然后在有利的水分条件下种子发芽和成苗。种子-DT在胚根出现后丢失；然而，有一个称为“DT 窗口”的发育时期，在此期间，发芽的种子可以根据周围低水势（即轻度渗透胁迫）的提示重新诱导 DT。DT窗口内的DT再诱导性已被用作模型生物系统，用于了解在许多植物物种中激活/抑制DT的分子机制。然而，对于农产工业特别重要的物种的DT窗口特征仍然很大程度上是分散的。在这里，进行了生理分析，旨在阐明番茄中 DT 窗口的特性，番茄是茄科的模式物种，在世界各地的种子工业和商业用途中占据着关键的战略地位。我们发现，（i）当发芽后发育中的胚根达到约 4 毫米时，番茄种子的 DT 窗口关闭，（ii）重新诱导 DT 进入种子的最有效的环境水势约为 -1.5 MPa，以及（iii）下胚轴的 DT 重新诱导具有器官特异性，在发芽后种子中显示出比子叶和根更长的 DT 窗口。