Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
Plant Cell Physiol. 2012 Feb;53(2):277-86. doi: 10.1093/pcp/pcr186. Epub 2011 Dec 22.
Phosphate (Pi) is a common limiter of plant growth due to its low availability in most soils. Plants have evolved elaborate mechanisms for sensing Pi deficiency and for initiating adaptive responses to low Pi conditions. Pi signaling pathways are modulated by both local and long-distance, or systemic, sensing mechanisms. Local sensing of low Pi initiates major root developmental changes aimed at enhancing Pi acquisition, whereas systemic sensing governs pathways that modulate expression of numerous genes encoding factors involved in Pi transport and distribution. The gaseous phytohormone ethylene has been shown to play an integral role in regulating local, root developmental responses to Pi deficiency. Comparatively, a role for ethylene in systemic Pi signaling has been more circumstantial. However, recent studies have revealed that ethylene acts to modulate a number of systemically controlled Pi starvation responses. Herein we highlight the findings from these studies and offer a model for how ethylene biosynthesis and responsiveness are integrated into both local and systemic Pi signaling pathways.
磷酸盐（Pi）是植物生长的常见限制因素，因为它在大多数土壤中的含量较低。植物已经进化出了精细的机制来感知 Pi 缺乏，并对低 Pi 条件发起适应性反应。Pi 信号通路受到局部和远距离（或系统）感应机制的调节。局部感知低 Pi 会引发主要的根发育变化，旨在增强 Pi 的获取，而系统感应则调节编码参与 Pi 运输和分配的众多基因表达的途径。已经表明气态植物激素乙烯在调节 Pi 缺乏时的局部、根发育反应中起着不可或缺的作用。相比之下，乙烯在系统 Pi 信号中的作用更为偶然。然而，最近的研究表明，乙烯可以调节许多系统控制的 Pi 饥饿反应。本文重点介绍了这些研究的发现，并提出了一个模型，说明乙烯的生物合成和反应性如何整合到局部和系统 Pi 信号通路中。
