Abstract

In temperate trees, optimal timing and quality of flowering directly depend on adequate winter dormancy progression, regulated by a combination of chilling and warm temperatures. Physiological, genetic and functional genomic studies have shown that hormones play a key role in bud dormancy establishment, maintenance and release. We combined physiological and transcriptional analyses, quantification of abscisic acid (ABA) and gibberellins (GAs), and modeling to further investigate how these signaling pathways are associated with dormancy progression in the flower buds of two sweet cherry cultivars. Our results demonstrated that GA-associated pathways have distinct functions and may be differentially related with dormancy. In addition, ABA levels rise at the onset of dormancy, associated with enhanced expression of ABA biosynthesis PavNCED genes, and decreased prior to dormancy release. Following the observations that ABA levels are correlated with dormancy depth, we identified PavUG71B6, a sweet cherry UDP-GLYCOSYLTRANSFERASE gene that up-regulates active catabolism of ABA to ABA glucosyl ester (ABA-GE) and may be associated with low ABA content in the early cultivar. Subsequently, we modeled ABA content and dormancy behavior in three cultivars based on the expression of a small set of genes regulating ABA levels. These results strongly suggest the central role of ABA pathway in the control of dormancy progression and open up new perspectives for the development of molecular-based phenological modeling.

中文翻译：

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激素信号的微调与甜樱桃花蕾中的休眠状态有关

摘要

在温带树木中，最佳的开花时间和开花质量直接取决于适当的冬季休眠进程，该过程由寒冷和温暖的温度共同调节。生理，遗传和功能基因组研究表明，激素在芽休眠的建立，维持和释放中起着关键作用。我们结合了生理和转录分析，脱落酸（ABA）和赤霉素（GAs）的定量，并进行建模以进一步研究这些信号通路如何与两个甜樱桃品种的花蕾中的休眠进程相关联。我们的结果表明，GA相关途径具有不同的功能，并且可能与休眠有差异。另外，在休眠开始时ABA水平升高，这与ABA生物合成的表达增强有关。PavNCED基因，并在休眠释放前降低。在观察到ABA水平与休眠深度相关之后，我们鉴定了PavUG71B6，这是一种甜樱桃UDP-糖基转移酶基因，其上调ABA的活性分解代谢为ABA葡萄糖基酯（ABA-GE），并且可能与低水平的ABA含量有关。早期品种。随后，我们基于少量调节ABA水平的基因的表达，对三个品种的ABA含量和休眠行为进行了建模。这些结果有力地表明了ABA途径在控制休眠进程中的核心作用，并为基于分子的物候模型的发展开辟了新的前景。