Seed germination is a pivotal period of plant growth and development. This process can be divided into four major stages, swelling absorption, seed coat dehiscence, radicle emergence and radicle elongation. Cupressus gigantea, a tree native to Tibet, China, is characterized by its resistance to stresses such as cold, and drought, and has a high economic and ecological value. Nevertheless, given its unique geographic location, its seeds are difficult to germinate. Therefore, it is crucial to explore the mechanisms involved in seed germination in this species to improve the germination efficiency of its seeds, thereby protecting this high-quality resource. Here, our findings indicate that seed germination was enhanced when exposed to a 6-h/8-h light/dark photoperiod, coupled with a temperature of 20°C. Furthermore, the application of exogenous GA3 (1 mg/ml, about 2.9 mM) stimulated the germination of C. gigantea seeds. Subsequently, proteomics was used to detect changes in protein expression during the four stages of seed germination. We identified 34 differentially expressed proteins (DEPs), including 13 at the radicle pre-emergence stage, and 17 at the radicle elongation stage. These DEPs were classified into eight functional groups, cytoskeletal proteins, energy metabolism, membrane transport, stress response, molecular chaperones, amino acid metabolism, antioxidant system and ABA signalling pathway. Most of them were found to be closely associated with amino acid metabolism. Combined, these findings indicate that, along with temperature and light, exogenous GA3 can increase the germination efficiency of C. gigantea seeds. Our study also offers insights into the changes in protein expression patterns in C. gigantea seeds during germination.

中文翻译：

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巨柏种子萌发不同阶段的蛋白质组学表征

种子发芽是植物生长发育的关键时期。这个过程可分为四个主要阶段：膨胀吸收、种皮开裂、胚根出现和胚根伸长。巨柏原产于中国西藏的树种，具有耐寒、耐旱等胁迫特性，具有较高的经济和生态价值。然而，由于其独特的地理位置，其种子很难发芽。因此，探讨该物种种子萌发的机制，提高其种子的萌发效率，保护这一优质资源至关重要。在这里，我们的研究结果表明，当暴露于 6 小时/8 小时的光照/黑暗光周期以及 20°C 的温度时，种子发芽率会增强。此外，外源GA的应用3（1 mg/ml，约 2.9 mM）刺激发芽巨茶种子。随后，利用蛋白质组学检测种子萌发四个阶段蛋白质表达的变化。我们鉴定了 34 个差异表达蛋白 (DEP)，其中 13 个处于胚根出苗前阶段，17 个处于胚根伸长阶段。这些DEP被分为八个功能组：细胞骨架蛋白、能量代谢、膜运输、应激反应、分子伴侣、氨基酸代谢、抗氧化系统和ABA信号通路。其中大多数被发现与氨基酸代谢密切相关。综合起来，这些发现表明，与温度和光照一起，外源 GA3可以提高发芽效率巨茶种子。我们的研究还提供了对蛋白质表达模式变化的见解巨茶种子在发芽期间。