背景回顾：The macronutrient phosphorus is essential for plant growth and development. Plants have evolved multiple strategies to increase the efficiency of phosphate (Pi) acquisition to protect themselves from Pi starvation. 

提出问题：However, the crosstalk between Pi homeostasis and plant development remains to be explored. 

结果1-mi399-PHO2-早衰：Here, we report that overexpressing microRNA399 (miR399) in maize (Zea mays) is associated with premature senescence after pollination. Knockout of ZmPHO2 (Phosphate 2), a miR399 target, resulted in a similar premature senescence phenotype. 

结果2-ID1-MIR399-PHO2-Pi稳态：Strikingly, we discovered that INDETERMINATE1 (ID1), a floral transition regulator, inhibits the transcription of ZmMIR399 genes by directly binding to their promoters, alleviating the repression of ZmPHO2 by miR399 and ultimately contributing to the maintenance of Pi homeostasis in maize. 

结果3-ID1自主调控：Unlike ZmMIR399 genes, whose expression is induced by Pi deficiency, ID1 expression was independent of the external inorganic orthophosphate status, indicating that ID1 is an autonomous regulator of Pi homeostasis. 

结果4-驯化：Furthermore, we show that ZmPHO2 was under selection during maize domestication and cultivation, resulting in a more sensitive response to Pi starvation in temperate maize than in tropical maize. 

结论：Our study reveals a direct functional link between Pi-deprivation sensing by the miR399-ZmPHO2 regulatory module and plant developmental regulation by ID1.

大量营养元素磷对于植物的生长和发育是必要的。植物演化出了多种策略以增加磷获取的高效性，从而保护自身免受磷饥饿。但是，Pi稳态和植物发育之间的交联仍不清楚。本文中，作者发现在玉米中过表达miR399与授粉后的提早衰老有关。敲除miR399的一个靶基因ZmPHO2会导致类似的提早衰老表型。有趣的是，做这发现成花转变调控子ID1能够通过直接结合到ZmMIR399的启动子抑制其表达，从而减缓了miR399对ZmPHO2的抑制作用，并最终导致玉米体内的Pi稳态。与ZmMIR399基因受到Pi缺乏转录激活不同，ID1的表达并不依赖于外部无机磷的状态，表明是一个Pi稳态的自主性调控子。此外，作者发现在玉米驯化和品种化过程中，ZmPHO2基因受到了选择，导致了温带玉米要比热带玉米对磷饥饿响应更加敏感。本文的研究结果揭示了一个由ID1介导的miR399-ZmPHO2调控模块介导的磷缺乏感知与植物发育之间的直接功能关联。

** 刘 琳 **