Transcription Profiles Reveal Sugar and Hormone Signaling Pathways Mediating Flower Induction in Apple (Malus domestica Borkh.)
Transcription Profiles Reveal Sugar and Hormone Signaling Pathways Mediating Flower Induction in Apple (Malus domestica Borkh.)
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DOI：
10.1093/pcp/pcv124
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发表时间：
2015-10-01
影响因子：
4.9
通讯作者：
Han, Ming-Yu
中科院分区：
文献类型：
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作者：
Xing, Li-Bo;Zhang, Dong;Han, Ming-Yu
苹果（Malus domestica Borkh.）的花诱导是由复杂的基因网络调控的，涉及多种信号通路，以确保来年花芽的形成，但苹果花诱导的分子决定因素尚不清楚。在这项研究中，来自分化芽的转录组谱使我们能够识别可能参与介导花诱导调节机制的信号通路的基因。通过对现有转录组学数据的分析，得出了苹果花诱导机制的假设模型，认为糖、激素、开花相关基因以及细胞周期诱导相关基因参与了苹果花的诱导过程。糖水平和代谢相关基因表达谱显示，蔗糖是诱导花的起始信号。涉及细胞分裂素（CK）、脱落酸（ABA）和赤霉素酸途径的复杂激素调节网络也能诱导苹果花的形成。CK在细胞形成和分化过程中发挥关键作用，并影响开花相关基因的表达水平。与此同时，芽体发育过程中ABA水平和ABA相关基因表达水平逐渐升高，糖代谢相关基因表达水平也逐渐升高，表明ABA信号通过参与糖介导的开花途径调控苹果花诱导。此外，芽中糖和淀粉沉积水平的变化可能受到ABA含量和ABA信号通路相关基因表达的影响。由此可见，以糖和激素信号串扰为主的多种途径调控着苹果树芽生长和诱导花的分子网络。
Flower induction in apple (Malus domestica Borkh.) is regulated by complex gene networks that involve multiple signal pathways to ensure flower bud formation in the next year, but the molecular determinants of apple flower induction are still unknown. In this research, transcriptomic profiles from differentiating buds allowed us to identify genes potentially involved in signaling pathways that mediate the regulatory mechanisms of flower induction. A hypothetical model for this regulatory mechanism was obtained by analysis of the available transcriptomic data, suggesting that sugar-, hormone- and flowering-related genes, as well as those involved in cell-cycle induction, participated in the apple flower induction process. Sugar levels and metabolism-related gene expression profiles revealed that sucrose is the initiation signal in flower induction. Complex hormone regulatory networks involved in cytokinin (CK), abscisic acid (ABA) and gibberellic acid pathways also induce apple flower formation. CK plays a key role in the regulation of cell formation and differentiation, and in affecting flowering-related gene expression levels during these processes. Meanwhile, ABA levels and ABA-related gene expression levels gradually increased, as did those of sugar metabolism-related genes, in developing buds, indicating that ABA signals regulate apple flower induction by participating in the sugar- mediated flowering pathway. Furthermore, changes in sugar and starch deposition levels in buds can be affected by ABA content and the expression of the genes involved in the ABA signaling pathway. Thus, multiple pathways, which are mainly mediated by crosstalk between sugar and hormone signals, regulate the molecular network involved in bud growth and flower induction in apple trees.