Shah Kamran, Zhu Xiaoyue, Zhang Tiantian, Chen Jiayi, Chen Jiaxuan, Qin Yonghua
Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
Int J Mol Sci. 2025 Jan 31;26(3):1250. doi: 10.3390/ijms26031250.
Flower induction in pitaya () is regulated by complex gene networks involving multiple signaling pathways that ensure flower bud (FB) formation, but its molecular determinants remain largely unknown. In this study, we aimed to identify key genes and pathways involved in pitaya flower induction by analyzing transcriptomics profiles from differentiating buds. Our results indicate that the flower induction process is driven by a combination of sugar, hormone, transcription factor (TF), and flowering-related genes. We found that during the FB induction period, the levels of sugar, starch, auxin (AUX), cytokinin (CTK) active forms dihydrozeatin riboside (dhZR), zeatin riboside (ZR), N6-isopentenyladenosine (iPA), and brassinosteroid (BR) increase in the late stage (LS), while active gibberellins (GA3, GA4) decrease, signaling a metabolic and hormonal shift essential for flowering. Differential gene expression analysis identified key genes involved in starch and sugar metabolism, AUX, CTK, BR synthesis, and (GA) degradation, with notable differential expression in photoperiod (, , ), age-related (), and key flowering pathways (, , , ). This study reveals a multidimensional regulatory network for FB formation in pitaya, primarily mediated by the crosstalk between sugar and hormone signaling pathways, providing new insights into the molecular mechanism of FB formation in pitaya.
火龙果（）中的成花诱导受涉及多个信号通路的复杂基因网络调控，这些信号通路确保花芽（FB）的形成，但其分子决定因素仍 largely 未知。在本研究中，我们旨在通过分析分化芽的转录组图谱来鉴定参与火龙果成花诱导的关键基因和通路。我们的结果表明，成花诱导过程由糖、激素、转录因子（TF）和开花相关基因共同驱动。我们发现，在 FB 诱导期，糖、淀粉、生长素（AUX）、细胞分裂素（CTK）的活性形式二氢玉米素核苷（dhZR）、玉米素核苷（ZR）、N6-异戊烯基腺嘌呤（iPA）和油菜素内酯（BR）的水平在后期（LS）升高，而活性赤霉素（GA3、GA4）降低，这表明代谢和激素转变对开花至关重要。差异基因表达分析确定了参与淀粉和糖代谢、AUX、CTK、BR 合成以及（GA）降解的关键基因，在光周期（，，）、年龄相关（）和关键开花通路（，，，）中具有显著差异表达。本研究揭示了火龙果 FB 形成的多维调控网络，主要由糖和激素信号通路之间的相互作用介导，为火龙果 FB 形成的分子机制提供了新的见解。
