Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies, Cadarache, 13108 St Paul Lez Durance, France.
Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
Plant Physiol. 2018 Apr;176(4):2943-2962. doi: 10.1104/pp.17.01246. Epub 2018 Feb 23.
Phosphate starvation-mediated induction of the HAD-type phosphatases PPsPase1 (AT1G73010) and PECP1 (AT1G17710) has been reported in Arabidopsis (). However, little is known about their in vivo function or impact on plant responses to nutrient deficiency. The preferences of PPsPase1 and PECP1 for different substrates have been studied in vitro but require confirmation in planta. Here, we examined the in vivo function of both enzymes using a reverse genetics approach. We demonstrated that PPsPase1 and PECP1 affect plant phosphocholine and phosphoethanolamine content, but not the pyrophosphate-related phenotypes. These observations suggest that the enzymes play a similar role in planta related to the recycling of polar heads from membrane lipids that is triggered during phosphate starvation. Altering the expression of the genes encoding these enzymes had no effect on lipid composition, possibly due to compensation by other lipid recycling pathways triggered during phosphate starvation. Furthermore, our results indicated that PPsPase1 and PECP1 do not influence phosphate homeostasis, since the inactivation of these genes had no effect on phosphate content or on the induction of molecular markers related to phosphate starvation. A combination of transcriptomics and imaging analyses revealed that PPsPase1 and PECP1 display a highly dynamic expression pattern that closely mirrors the phosphate status. This temporal dynamism, combined with the wide range of induction levels, broad expression, and lack of a direct effect on Pi content and regulation, makes PPsPase1 and PECP1 useful molecular markers of the phosphate starvation response.
磷酸盐饥饿诱导的 HAD 型磷酸酶 PPpase1（AT1G73010）和 PECP1（AT1G17710）在拟南芥中已有报道（）。然而，它们在体内的功能或对植物响应养分缺乏的影响知之甚少。虽然已经在体外研究了 PPpase1 和 PECP1 对不同底物的偏好，但需要在体内进行确认。在这里，我们使用反向遗传学方法研究了这两种酶的体内功能。我们证明了 PPpase1 和 PECP1 影响植物磷酸胆碱和磷酸乙醇胺的含量，但不影响焦磷酸盐相关表型。这些观察结果表明，这些酶在植物体内发挥相似的作用，与在磷酸盐饥饿时从膜脂质中回收极性头有关。改变编码这些酶的基因的表达对脂质组成没有影响，这可能是由于在磷酸盐饥饿时触发的其他脂质回收途径的补偿。此外，我们的结果表明，PPpase1 和 PECP1 不影响磷酸盐稳态，因为这些基因的失活对磷酸盐含量或与磷酸盐饥饿相关的分子标记物的诱导没有影响。转录组学和成像分析的组合表明，PPpase1 和 PECP1 表现出高度动态的表达模式，与磷酸盐状态密切相关。这种时间动态性，加上广泛的诱导水平、广泛的表达以及对 Pi 含量和调节没有直接影响，使得 PPpase1 和 PECP1 成为磷酸盐饥饿反应的有用分子标记物。
