Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/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.
Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Plant Sci. 2024 Nov;348:112240. doi: 10.1016/j.plantsci.2024.112240. Epub 2024 Aug 28.
Pitaya, a desert plant, has an underexplored flowering mechanism due to a lack of functional validation assays. This study reveals that the transition from vegetative to generative growth in pitaya is regulated by significant metabolic shift, underscoring the importance of understanding and address the challenging issue pitaya's phase change. Lateral buds from 6-years-old 'Guanhuahong' pitaya (Hylocereus monacanthus) plants were collected on April 8th, 18th, and 28th 2023, representing early, middle, and late stages of phase transition, respectively. Results showed diminished nitrogen levels concurrent with increased carbon levels and carbon-to-nitrogen (C/N) ratios during pitaya phase transition. Transcriptomic analysis identified batches of differentially expressed genes (DEGs) involved in downregulating nitrogen metabolism and upregulating carbon metabolism. These batches of genes play a central role in the metabolic shifts that predominantly regulate the transition to the generative phase in pitaya. This study unveils the intricate regulatory network involving 6 sugar synthesis and transport, 11 photoperiod (e.g., PHY, CRY, PIF) and 6 vernalization (e.g., VIN3) pathways, alongside 11 structural flowering genes (FCA, FLK, LFY, AGL) out of a vast array of potential candidates in pitaya phase change. These findings provide insights into the metabolic pathways involved in pitaya's phase transition, offering a theoretical framework for managing flowering, guiding breeding strategies to optimize flowering timing and improve crop yields under varied nitrogen conditions.
火龙果是一种沙漠植物，由于缺乏功能验证检测，其开花机制尚未得到充分研究。本研究揭示了火龙果从营养生长到生殖生长的转变受显著代谢变化的调控，突出了理解和解决火龙果相变这一具有挑战性问题的重要性。2023 年 4 月 8 日、18 日和 28 日，分别采集了 6 年生‘观音红’火龙果（Hylocereus monacanthus）的侧芽，代表相变的早期、中期和晚期阶段。结果表明，在火龙果相变过程中，氮含量降低，而碳含量增加，碳氮比（C/N）升高。转录组分析鉴定出参与下调氮代谢和上调碳代谢的一批差异表达基因（DEGs）。这些基因批次在代谢变化中发挥核心作用，主要调控火龙果向生殖期的转变。本研究揭示了涉及 6 个糖合成和转运、11 个光周期（如 PHY、CRY、PIF）和 6 个春化（如 VIN3）途径，以及 11 个结构开花基因（FCA、FLK、LFY、AGL）的复杂调控网络，这些基因在火龙果相变的众多潜在候选基因中具有重要作用。这些发现为火龙果相变涉及的代谢途径提供了深入了解，为管理开花、指导优化开花时间的选育策略提供了理论框架，并改善了在不同氮条件下的作物产量。
