The medicinal herb Artemisia annua L. is prized for its capacity to generate artemisinin, which is used to cure malaria. Potentially influencing the biomass and secondary metabolite synthesis of A. annua is plant nutrition, particularly phosphorus (P). However, most soil P exist as insoluble inorganic and organic phosphates, which results to low P availability limiting plant growth and development. Although plants have developed several adaptation strategies to low P levels, genetics and metabolic responses to P status remain largely unknown. In a controlled greenhouse experiment, the sparingly soluble P form, hydroxyapatite (Ca₅OH(PO₄)₃/CaP) was used to simulate calcareous soils with low P availability. In contrast, the soluble P form KH₂PO₄/KP was used as a control. A. annua’s morphological traits, growth, and artemisinin concentration were determined, and RNA sequencing was used to identify the differentially expressed genes (DEGs) under two different P forms. Total biomass, plant height, leaf number, and stem diameter, as well as leaf area, decreased by 64.83%, 27.49%, 30.47%, 38.70%, and 54.64% in CaP compared to KP; however, LC–MS tests showed an outstanding 37.97% rise in artemisinin content per unit biomass in CaP contrary to KP. Transcriptome analysis showed 2015 DEGs (1084 up-regulated and 931 down-regulated) between two P forms, including 39 transcription factor (TF) families. Further analysis showed that DEGs were mainly enriched in carbohydrate metabolism, secondary metabolites biosynthesis, enzyme catalytic activity, signal transduction, and so on, such as tricarboxylic acid (TCA) cycle, glycolysis, starch and sucrose metabolism, flavonoid biosynthesis, P metabolism, and plant hormone signal transduction. Meanwhile, several artemisinin biosynthesis genes were up-regulated, including DXS, GPPS, GGPS, MVD, and ALDH, potentially increasing artemisinin accumulation. Furthermore, 21 TF families, including WRKY, MYB, bHLH, and ERF, were up-regulated in reaction to CaP, confirming their importance in P absorption, internal P cycling, and artemisinin biosynthesis regulation. Our results will enable us to comprehend how low P availability impacts the parallel transcriptional control of plant development, growth, and artemisinin production in A. annua. This study could lay the groundwork for future research into the molecular mechanisms underlying A. annua’s low P adaptation.

药草Artemisia annua L。因其产生青蒿素的能力而备受赞誉，青蒿素可用于治疗疟疾。植物营养，特别是磷（P），可能影响青蒿的生物量和次生代谢物合成。然而，大多数土壤磷以不溶性无机和有机磷酸盐形式存在，导致磷利用率低，限制了植物的生长和发育。尽管植物已经制定了几种针对低磷水平的适应策略，但对磷状态的遗传和代谢反应仍然很大程度上未知。在受控温室实验中，使用难溶性磷形式羟基磷灰石 (Ca ₅ OH(PO ₄ ) ₃ /CaP) 来模拟磷利用率低的钙质土壤。相反，可溶性P形式KH ₂ PO ₄ /KP用作对照。测定青蒿的形态性状、生长情况和青蒿素浓度，并利用RNA测序鉴定两种不同P形态下的差异表达基因（DEG）。与KP相比，CaP的总生物量、株高、叶数、茎粗和叶面积分别下降了64.83%、27.49%、30.47%、38.70%和54.64%；然而，LC-MS 测试显示，与 KP 相比，CaP 中单位生物量的青蒿素含量显着增加了 37.97%。转录组分析显示两种 P 形式之间存在 2015 个 DEG（1084 个上调和 931 个下调），包括 39 个转录因子 (TF) 家族。进一步分析发现DEGs主要富集在碳水化合物代谢、次生代谢物生物合成、酶催化活性、信号转导等方面，如三羧酸（TCA）循环、糖酵解、淀粉和蔗糖代谢、类黄酮生物合成、磷代谢等。植物激素信号转导。同时，一些青蒿素生物合成基因上调，包括DXS、GPPS、GGPS、MVD和ALDH，可能增加青蒿素的积累。此外，包括 WRKY、MYB、bHLH 和 ERF 在内的 21 个 TF 家族在 CaP 反应中上调，证实了它们在磷吸收、内部磷循环和青蒿素生物合成调节中的重要性。我们的结果将使我们能够理解低磷利用率如何影响青蒿植物发育、生长和青蒿素生产的平行转录控制。这项研究可以为未来研究青蒿低磷适应的分子机制奠定基础。