Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221005, UP, India.
Plant Stress Physiology and Biotechnology Section, Nuclear Agriculture & Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Int J Mol Sci. 2018 Jun 29;19(7):1914. doi: 10.3390/ijms19071914.
Phosphorus (P) is an essential element required for incorporation into several biomolecules and for various biological functions; it is, therefore, vital for optimal growth and development of plants. The extensive research on identifying the processes underlying the uptake, transport, and homeostasis of phosphate (Pi) in various plant organs yielded valuable information. The transport of Pi occurs from the soil into root epidermal cells, followed by loading into the root xylem vessels for distribution into other plant organs. Under conditions of Pi deficiency, Pi is also translocated from the shoot to the root via the phloem. Vacuoles act as a storage pool for extra Pi, enabling its delivery to the cytosol, a process which plays an important role in the homeostatic control of cytoplasmic Pi levels. In mitochondria and chloroplasts, Pi homeostasis regulates ATP synthase activity to maintain optimal ATP levels. Additionally, the endoplasmic reticulum functions to direct Pi transporters and Pi toward various locations. The intracellular membrane potential and pH in the subcellular organelles could also play an important role in the kinetics of Pi transport. The presented review provides an overview of Pi transport mechanisms in subcellular organelles, and also discusses how they affect Pi balancing at cellular, tissue, and whole-plant levels.
磷（P）是植物生长和发育所必需的元素，它需要整合到多种生物分子中并参与各种生物学功能。对植物各器官中磷（Pi）吸收、运输和稳态的内在过程的广泛研究提供了有价值的信息。Pi 的运输从土壤进入根表皮细胞，然后装载到根木质部导管中，以分配到其他植物器官。在缺磷条件下，Pi 也可以通过韧皮部从地上部分转运到根。液泡作为额外 Pi 的储存池，使其能够输送到细胞质，这一过程在细胞质 Pi 水平的稳态控制中起着重要作用。在线粒体和叶绿体中，Pi 的稳态调节 ATP 合酶的活性以维持最佳的 ATP 水平。此外，内质网的功能是将 Pi 转运蛋白和 Pi 引导到不同的位置。细胞内细胞器的膜电位和 pH 值也可能在 Pi 运输的动力学中发挥重要作用。本文综述了亚细胞细胞器中 Pi 转运的机制，并讨论了它们如何影响细胞、组织和整个植物水平的 Pi 平衡。
