Department of Plant Breeding, Fruit Breeding Group, CEBAS-CSIC, PO Box 164, 30100 Espinardo, Murcia, Spain.
Keygene N.V., Agro Business Park 90, 6708 PW Wageningen, The Netherlands.
Tree Physiol. 2021 Apr 8;41(4):589-605. doi: 10.1093/treephys/tpaa151.
Flower bud dormancy in temperate fruit tree species, such as almond [Prunus dulcis (Mill.) D.A. Webb], is a survival mechanism that ensures that flowering will occur under suitable weather conditions for successful flower development, pollination and fruit set. Dormancy is divided into three sequential phases: paradormancy, endodormancy and ecodormancy. During the winter, buds need cultivar-specific chilling requirements (CRs) to overcome endodormancy and heat requirements to activate the machinery to flower in the ecodormancy phase. One of the main factors that enables the transition from endodormancy to ecodormancy is transcriptome reprogramming. In this work, we therefore monitored three almond cultivars with different CRs and flowering times by RNA sequencing during the endodormancy release of flower buds and validated the data by quantitative real-time PCR in two consecutive seasons. We were thus able to identify early and late flowering time candidate genes in endodormant and ecodormant almond flower buds associated with metabolic switches, transmembrane transport, cell wall remodeling, phytohormone signaling and pollen development. These candidate genes were indeed involved in the overcoming of the endodormancy in almond. This information may be used for the development of dormancy molecular markers, increasing the efficiency of temperate fruit tree breeding programs in a climate-change context.
温带果树如巴旦杏（Prunus dulcis (Mill.) D.A. Webb）的花芽休眠是一种生存机制，可确保在适宜的天气条件下开花，以实现成功的花发育、授粉和结实。休眠分为三个连续的阶段：前期休眠、内生休眠和生态休眠。在冬季，芽需要特定品种的需冷量（CRs）来克服内生休眠，并需要热量来激活生态休眠阶段的开花机制。使内生休眠向生态休眠转变的主要因素之一是转录组重编程。因此，在本研究中，我们通过 RNA 测序监测了三个具有不同 CRs 和开花时间的巴旦杏品种，在芽的内生休眠解除过程中进行监测，并在两个连续的季节通过定量实时 PCR 对数据进行了验证。我们因此鉴定出与代谢转换、跨膜运输、细胞壁重塑、植物激素信号和花粉发育相关的早期和晚期开花时间候选基因，这些候选基因确实与巴旦杏的内生休眠的解除有关。这些信息可用于休眠分子标记的开发，提高气候变化背景下温带果树育种计划的效率。
