背景回顾：Phosphorus (P) is a major element required for plant growth and development. To cope with P shortage, plants activate local and long-distance signaling pathways, such as the increase in the production and exudation of strigolactones (SLs). The role of the latter in mitigating P deficiency is, however, still largely unknown. 

主要发现：To shed light on this, we studied the transcriptional response to P starvation and replenishment in wild-type rice and a SL mutant, dwarf10 (d10), and upon exogenous application of the synthetic SL GR24. 

结果1-磷饥饿响应：P starvation resulted in major transcriptional alterations, such as the upregulation of P TRANSPORTER, SYG1/PHO81/XPR1 (SPX) and VACUOLAR PHOSPHATE EFFLUX TRANSPORTER. Gene Ontology (GO) analysis of the genes induced by P starvation showed enrichment in phospholipid catabolic process and phosphatase activity. In d10, P deficiency induced upregulation of genes enriched for sesquiterpenoid production, secondary shoot formation, and metabolic processes, including lactone biosynthesis. 

结果2-SL处理与磷饥饿响应：Furthermore, several genes induced by GR24 treatment shared the same GO terms with P starvation-induced genes, such as oxidation reduction, heme binding and oxidoreductase activity, hinting at the role that SLs play in the transcriptional reprogramming upon P starvation. 

结果3-SL前体：Gene co-expression network analysis uncovered a METHYL TRANSFERASEthat displayed co-regulation with known rice SL biosynthetic genes. Functional characterization showed that this gene encodes an enzyme catalyzing the conversion of carlactonoic acid to methyl carlactonoate. 

结论：Our work provides a valuable resource to further studies on the response of crops to P deficiency and reveals a tool for the discovery of new SL biosynthetic genes.

 摘 要 

磷是植物生长和发育的主要营养元素之一。为了应对磷短缺，植物会激活局域和长距离的信号转导途径，如独角金内酯（SLs）产量和分泌的增加。至于独角金内酯如何缓解磷缺乏还不清楚。本文中，作者比较了野生型水稻和SL突变体dwarf10对磷饥饿、补给以及外施人工合成SL类似物GR24的转录响应。磷饥饿会导致明显的转录变化，比如磷转运蛋白编码基因SPX和液泡磷外流转运蛋白编码基因VPT。GO分析显示磷饥饿诱导基因主要富集在磷脂分解代谢过程与磷酸酶活性。在dwarf10突变体中，磷缺乏会诱导半萜生产、次生芽形成以及包括内酯生物合成在内的代谢过程相关基因的上调表达。此外，GR24处理和磷饥饿诱导基因具有部分重叠的GO条目，比如氧化还原、heme结合以及氧化还原酶活性，暗示SLs在植物响应磷饥饿时的转录重编程中发挥作用。基因共表达网络分析显示一个甲基转移酶编码基因表现出与水稻SL生物合成基因的表达共调控。功能鉴定显示该基因编码一个将己内酯酸转化为甲基化己内酯的酶。本文的结果为作物磷缺乏响应的研究提供了珍贵的资源，同时也为新的SL生物合成基因挖掘提供了一个工具。