Protein Science Laboratory of the Ministry of Education, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
New Phytol. 2011 Mar;189(4):1084-1095. doi: 10.1111/j.1469-8137.2010.03555.x. Epub 2010 Nov 30.
• With the exception of root hair development, the role of the phytohormone ethylene is not clear in other aspects of plant responses to inorganic phosphate (Pi) starvation. • The induction of AtPT2 was used as a marker to find novel signalling components involved in plant responses to Pi starvation. Using genetic and chemical approaches, we examined the role of ethylene in the regulation of plant responses to Pi starvation. • hps2, an Arabidopsis mutant with enhanced sensitivity to Pi starvation, was identified and found to be a new allele of CTR1 that is a key negative regulator of ethylene responses. 1-aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, increases plant sensitivity to Pi starvation, whereas the ethylene perception inhibitor Ag+ suppresses this response. The Pi starvation-induced gene expression and acid phosphatase activity are also enhanced in the hps2 mutant, but suppressed in the ethylene-insensitive mutant ein2-5. By contrast, we found that ethylene signalling plays a negative role in Pi starvation-induced anthocyanin production. • These findings extend the roles of ethylene in the regulation of plant responses to Pi starvation and will help us to gain a better understanding of the molecular mechanism underlying these responses.
• 除了根毛发育，植物对无机磷（Pi）饥饿的反应中，植物激素乙烯的作用并不明确。• 诱导 AtPT2 的表达被用作标记，以寻找参与植物对 Pi 饥饿反应的新信号成分。我们使用遗传和化学方法，研究了乙烯在调节植物对 Pi 饥饿反应中的作用。• hps2 是一种对 Pi 饥饿敏感性增强的拟南芥突变体，被鉴定为 CTR1 的一个新等位基因，CTR1 是乙烯反应的关键负调控因子。1-氨基环丙烷-1-羧酸（ACC），乙烯的前体，增加植物对 Pi 饥饿的敏感性，而乙烯感受抑制剂 Ag+ 抑制了这种反应。hps2 突变体中 Pi 饥饿诱导的基因表达和酸性磷酸酶活性也增强，但在乙烯不敏感突变体 ein2-5 中受到抑制。相比之下，我们发现乙烯信号在 Pi 饥饿诱导的花青素合成中起着负作用。• 这些发现扩展了乙烯在调节植物对 Pi 饥饿反应中的作用，并将帮助我们更好地理解这些反应的分子机制。
