Abstract：
To survive in the dry state, orthodox seeds acquire desiccation tolerance. As maturation progresses, the seeds gradually acquire longevity, which is the total timespan during which the dry seeds remain viable. The desiccation-tolerance mechanism(s) allow seeds to remain dry without losing their ability to germinate. This adaptive trait has played a key role in the evolution of land plants. Understanding the mechanisms for seed survival after desiccation is one of the central goals still unsolved. That is, the cellular protection during dry state and cell repair during rewatering involves a not entirely known molecular network(s). Although desiccation tolerance is retained in seeds of higher plants, resurrection plants belonging to different plant lineages keep the ability to survive desiccation in vegetative tissue. Abscisic acid (ABA) is involved in desiccation tolerance through tight control of the synthesis of unstructured late embryogenesis abundant (LEA) proteins, heat shock thermostable proteins (sHSPs), and non-reducing oligosaccharides. During seed maturation, the progressive loss of water induces the formation of a so-called cellular \"glass state\". This glassy matrix consists of soluble sugars, which immobilize macromolecules offering protection to membranes and proteins. In this way, the secondary structure of proteins in dry viable seeds is very stable and remains preserved. ABA insensitive-3 (ABI3), highly conserved from bryophytes to Angiosperms, is essential for seed maturation and is the only transcription factor (TF) required for the acquisition of desiccation tolerance and its re-induction in germinated seeds. It is noteworthy that chlorophyll breakdown during the last step of seed maturation is controlled by ABI3. This update contains some current results directly related to the physiological, genetic, and molecular mechanisms involved in survival to desiccation in orthodox seeds. In other words, the mechanisms that facilitate that an orthodox dry seed is a living entity.
摘要：
为了在干燥状态下生存，正统种子获得脱水耐受性。随着成熟的进展，种子逐渐获得长寿，这是干种子保持存活的总时间跨度。脱水耐受机制允许种子保持干燥而不丧失其发芽能力。这种适应性性状在陆地植物的进化中起着关键作用。了解干燥后种子存活的机制是尚未解决的中心目标之一。也就是说,在干燥状态下的细胞保护和在复水期间的细胞修复涉及不完全已知的分子网络。尽管高等植物的种子保留了脱水耐受性，属于不同植物谱系的复活植物保持在营养组织中存活干燥的能力。脱落酸（ABA）通过严格控制非结构化晚期胚胎发生丰富（LEA）蛋白的合成而参与脱水耐受性。热休克热稳定蛋白（sHSPs），和非还原性寡糖。在种子成熟期间,水的逐渐流失会导致形成所谓的细胞“玻璃态”。这种玻璃状基质由可溶性糖组成，固定大分子，为膜和蛋白质提供保护。这样,干燥的有活力种子中蛋白质的二级结构非常稳定，并保持保存。ABA不敏感-3(ABI3),从苔藓植物到被子植物高度保守，对于种子成熟至关重要，并且是获得脱水耐受性及其在发芽种子中的再诱导所需的唯一转录因子（TF）。值得注意的是,在种子成熟的最后步骤期间的叶绿素分解由ABI3控制。此更新包含一些与生理直接相关的当前结果，遗传,以及正统种子存活到干燥的分子机制。换句话说,促进正统干种子是有生命的实体的机制。
