RESULTS: Treatments with gibberellins showed different efficacies and pointed out a timeframe of maximum inhibition of floral transition in peach buds. Contextually, APETALA1 gene expression was shown to be a reliable marker of gibberellin efficacy in controlling this process. RNA-Seq transcriptomic analyses allowed to identify specific genes dealing with ROS, cell cycle, T6P, floral induction control and other processes, which are correlated with the bud sensitivity to gibberellins and possibly involved in bud development during its transition to the reproductive stage. Transcriptomic data integrated with the quantification of the main bioactive hormones in the bud allowed to identify the main hormonal regulators of floral transition in peach, with a pivotal role played by endogenous gibberellins and cytokinins.
CONCLUSIONS: The peach bud undergoes different levels of receptivity to gibberellin inhibition. The stage with maximum responsiveness corresponded to a transcriptional and hormonal crossroad, involving both flowering inhibitors and inductors. Endogenous gibberellin levels increased only at the latest developmental stage, when floral transition was already partially achieved, and the bud was less sensitive to exogenous treatments. A physiological model summarizes the main findings and suggests new research ideas to improve our knowledge about floral transition in peach.
结果:用赤霉素处理显示出不同的功效,并指出了最大抑制桃芽中花过渡的时间范围。上下文中,APETALA1基因表达被证明是控制该过程的赤霉素功效的可靠标记。RNA-Seq转录组学分析允许鉴定处理ROS的特定基因,细胞周期,T6P,花卉诱导控制和其他过程,这与芽对赤霉素的敏感性相关,并且可能在其向生殖阶段过渡期间参与芽的发育。转录组数据与芽中主要生物活性激素的定量相结合,可以确定桃花过渡的主要激素调节剂,内源性赤霉素和细胞分裂素起关键作用。
结论:桃芽经历不同程度的赤霉素抑制的接受性。具有最大反应性的阶段对应于转录和激素的十字路口,涉及开花抑制剂和诱导剂。内源性赤霉素水平仅在最新的发育阶段增加,当花卉过渡已经部分实现时,芽对外源处理不太敏感。生理模型总结了主要发现,并提出了新的研究思路,以提高我们对桃花过渡的认识。