Abstract：
CONCLUSIONS: The hop phenological cycle was described in subtropical condition of Brazil showing that flowering can happen at any time of year and this was related to developmental molecular pathways. Hops are traditionally produced in temperate regions, as it was believed that vernalization was necessary for flowering. Nevertheless, recent studies have revealed the potential for hops to flower in tropical and subtropical climates. In this work, we observed that hops in the subtropical climate of Minas Gerais, Brazil grow and flower multiple times throughout the year, independently of the season, contrasting with what happens in temperate regions. This could be due to the photoperiod consistently being inductive, with daylight hours below the described threshold (16.5 h critical). We observed that when the plants reached 7-9 nodes, the leaves began to transition from heart-shaped to trilobed-shaped, which could be indicative of the juvenile to adult transition. This could be related to the fact that the 5th node (in plants with 10 nodes) had the highest expression of miR156, while two miR172s increased in the 20th node (in plants with 25 nodes). Hop flowers appeared later, in the 25th or 28th nodes, and the expression of HlFT3 and HlFT5 was upregulated in plants between 15 and 20 nodes, while the expression of HlTFL3 was upregulated in plants with 20 nodes. These results indicate the role of axillary meristem age in regulating this process and suggest that the florigenic signal should be maintained until the hop plants bloom. In addition, it is possible that the expression of TFL is not sufficient to inhibit flowering in these conditions and promote branching. These findings suggest that the reproductive transition in hop under inductive photoperiodic conditions could occur in plants between 15 and 20 nodes. Our study sheds light on the intricate molecular mechanisms underlying hop floral development, paving the way for potential advancements in hop production on a global scale.
摘要：
结论：在巴西亚热带条件下描述了啤酒花的物候周期，表明开花可以在一年中的任何时候发生，这与发育分子途径有关。啤酒花传统上是在温带地区生产的，因为人们认为春化是开花所必需的。然而，最近的研究揭示了在热带和亚热带气候下啤酒花的潜力。在这项工作中,我们观察到米纳斯吉拉斯州亚热带气候的啤酒花，巴西全年多次生长和开花，独立于季节，与温带地区的情况形成对比。这可能是由于光周期始终是感应的，日光小时低于所述阈值(16.5小时临界)。我们观察到，当植物到达7-9个节点时，叶子开始从心形过渡到三叶形，这可能预示着青少年向成人的过渡。这可能与以下事实有关:第5节点(在具有10个节点的植物中)具有最高的miR156表达,而两个miR172在第20节点(在具有25个节点的植物中)中增加。后来出现了合花，在第25或28个节点中，HlFT3和HlFT5的表达在15至20个节点之间上调，而HlTFL3的表达在具有20个节点的植物中上调。这些结果表明腋生分生组织年龄在调节该过程中的作用，并建议应保持成花信号直到啤酒花植物开花。此外,TFL的表达可能不足以在这些条件下抑制开花并促进分枝。这些发现表明，在诱导光周期条件下，啤酒花的生殖转变可能发生在15至20个节点之间的植物中。我们的研究揭示了啤酒花发育背后复杂的分子机制，为全球范围内啤酒花生产的潜在进步铺平了道路。
