ABSTRACT Seed dormancy is an adaptation key to survival in conditions unsuitable for growth. In pear (Pyrus calleryana Decne), phytohormones participate in the release of seed dormancy. However, the involvement of carbohydrate metabolism in this process is still unclear. In the present study, we determined the sucrose, starch, and glucose levels during seed dormancy release. Sucrose and starch content decreased, whereas glucose levels increased. Consistent with these changes in carbohydrate content, the activity levels of sucrose synthase (SS) and α-amylase increased because they cleavaged sucrose and starch, respectively. In contrast, sucrose phosphate synthase (SPS) activity decreased during seed dormancy release. This latter enzyme catalyzes sucrose synthesis. Seed dormancy release was decreased during stratification in the presence of an antisense oligonucleotides (As-ODN) for PcaSS8. Moreover, sucrose levels increased and the activities of SS and α-amylase decreased during seed dormancy release after the treatment of As-ODN. Taken together, our results suggest that sucrose synthase plays an important role in regulating carbohydrate metabolism during seed dormancy release in P. calleryana.

中文翻译：

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蔗糖合酶参与基于碳水化合物代谢的 Pyrus calleryana Decne 种子休眠释放调节

摘要 种子休眠是在不适合生长的条件下生存的关键。在梨 (Pyrus calleryana Decne) 中，植物激素参与种子休眠的解除。然而，碳水化合物代谢在这一过程中的参与尚不清楚。在本研究中，我们确定了种子休眠解除期间的蔗糖、淀粉和葡萄糖水平。蔗糖和淀粉含量减少，而葡萄糖水平增加。与碳水化合物含量的这些变化一致，蔗糖合酶 (SS) 和 α-淀粉酶的活性水平增加，因为它们分别裂解蔗糖和淀粉。相比之下，蔗糖磷酸合酶 (SPS) 活性在种子休眠解除期间降低。后一种酶催化蔗糖合成。在 PcaSS8 的反义寡核苷酸 (As-ODN) 存在的情况下，分层期间种子休眠释放减少。此外，在As-ODN处理后种子休眠解除期间，蔗糖水平增加，SS和α-淀粉酶的活性降低。总之，我们的结果表明蔗糖合酶在 P. calleryana 种子休眠释放过程中调节碳水化合物代谢中起着重要作用。