BACKGROUND Grape buds exhibit non-uniform, or delayed, break in early spring in subtropical regions because the accumulation of chilling is insufficient. Hydrogen cyanamide (H2CN2, HC) can partially replace chilling to effectively promote bud sprouting and is used widely in warm winter areas. However, the exact underlying mechanism of grape bud release from endodormancy induced by HC remains elusive. RESULTS In this study, the transcriptome of grape winter buds under in vitro conditions following HC and water treatment (control) was analyzed using RNA-seq technology. A total of 6772 differentially expressed genes (DEGs) were identified. Furthermore, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that starch and sucrose metabolism and plant hormone signaling transduction were most enriched out of the 50 total pathways. HC treatment induced the upregulated expression of sucrose synthase (SUS), sucrose phosphate synthase (SPS), α-amylase (AM), and β-amylase (BM) and downregulated expression of sucrose invertase (INV), hexokinase (HK), fructokinase (FK), soluble starch synthase (SS), and granule-bound starch synthase (GBSS). Hence, the starch concentration in the HC-treated group was significantly lower than that in control, whereas soluble sugar content in the HC-treated group increased quickly and was higher than that in control between 0 and 8 d. The concentration of indoleacetic acid (IAA) and zeatin (ZT) increased, whereas that of abscisic acid (ABA) and gibberellin (GA) decreased in HC treated group, which coincided with the expression level of genes involved in above hormone signals. The content of hydrogen peroxide (H2O2) and enzyme activity of superoxide dismutase (SOD) and peroxidase (POD) were increased in grape buds with HC treatment, whereas catalase (CAT) activity was decreased. HC treatment increased the expression of POD, SOD, primary amine oxidase (PAO), polyamine oxidase (PAOX), and glutathione peroxidase (GSH-Px). CONCLUSION Based on these results, it is possible to propose a mechanistic model that underlies the regulation of endodormancy release in grapevine buds by exogenous HC application.

中文翻译：

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氰氨化氢通过碳水化合物代谢和植物激素信号传导诱导葡萄芽的内在气味释放。

背景技术由于寒冷的积累不足，所以在亚热带地区，早春的葡萄芽表现出不均匀或延迟的破裂。氰氨化氢（H2CN2，HC）可以部分替代冷却，有效地促进芽萌芽，并在温暖的冬季地区广泛使用。但是，由HC引起的内在气味释放葡萄芽的确切机理尚不清楚。结果在这项研究中，使用RNA-seq技术分析了经过HC和水处理（对照）的体外条件下葡萄冬芽的转录组。总共鉴定了6772个差异表达基因（DEG）。此外，基因本体论（GO）和《京都基因与基因组百科全书》（KEGG）分析表明，淀粉和蔗糖代谢以及植物激素信号转导在50种总途径中最为丰富。HC处理诱导了蔗糖合酶（SUS），蔗糖磷酸合酶（SPS），α-淀粉酶（AM）和β-淀粉酶（BM）的表达上调以及蔗糖转化酶（INV），己糖激酶（HK），果糖激酶的表达下调（FK），可溶性淀粉合成酶（SS）和颗粒结合淀粉合成酶（GBSS）。因此，HC处理组中的淀粉浓度显着低于对照组，而HC处理组中的可溶性糖含量迅速增加，且在0至8 d时高于对照组。吲哚乙酸（IAA）和玉米素（ZT）的浓度增加，HC处理组脱落酸（ABA）和赤霉素（GA）的表达降低，这与上述激素信号中涉及的基因的表达水平相吻合。HC处理的葡萄芽中过氧化氢（H2O2）含量和超氧化物歧化酶（SOD）和过氧化物酶（POD）的酶活性增加，而过氧化氢酶（CAT）的活性降低。HC处理可增加POD，SOD，伯胺氧化酶（PAO），聚胺氧化酶（PAOX）和谷胱甘肽过氧化物酶（GSH-Px）的表达。结论基于这些结果，有可能提出一种机制模型，该模型可通过外源HC的应用来调节葡萄芽中内在气味的释放。HC处理的葡萄芽中过氧化氢（H2O2）含量和超氧化物歧化酶（SOD）和过氧化物酶（POD）的酶活性增加，而过氧化氢酶（CAT）的活性降低。HC处理可增加POD，SOD，伯胺氧化酶（PAO），聚胺氧化酶（PAOX）和谷胱甘肽过氧化物酶（GSH-Px）的表达。结论基于这些结果，有可能提出一种机制模型，该模型可通过外源HC的应用来调节葡萄芽中内在气味的释放。HC处理的葡萄芽中过氧化氢（H2O2）含量和超氧化物歧化酶（SOD）和过氧化物酶（POD）的酶活性增加，而过氧化氢酶（CAT）的活性降低。HC处理可增加POD，SOD，伯胺氧化酶（PAO），多胺氧化酶（PAOX）和谷胱甘肽过氧化物酶（GSH-Px）的表达。结论基于这些结果，有可能提出一种机制模型，该模型可通过外源HC的应用来调节葡萄芽中内在气味的释放。和谷胱甘肽过氧化物酶（GSH-Px）。结论基于这些结果，有可能提出一种机制模型，该模型可通过外源HC的应用来调节葡萄芽中内在气味的释放。和谷胱甘肽过氧化物酶（GSH-Px）。结论基于这些结果，有可能提出一种机制模型，该模型可通过外源HC的应用来调节葡萄芽中内在气味的释放。