Early Extracellular ATP Signaling in Arabidopsis Root Epidermis: A Multi-Conductance Process
Early Extracellular ATP Signaling in Arabidopsis Root Epidermis: A Multi-Conductance Process
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DOI：
10.3389/fpls.2019.01064
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发表时间：
2019-09-04
影响因子：
5.6
通讯作者：
Davies, Julia M.
中科院分区：
文献类型：
--
作者：
Wang, Limin;Stacey, Gary;Davies, Julia M.
腺苷5'-三磷酸（ATP）是一种重要的细胞外信号因子，在生长调节、气孔调节等方面起作用。电导和伤口反应。随着第一个在植物中发现的细胞外ATP受体（P2K1/DORN1）和一种质膜NADPH氧化酶作为其靶标，研究人员继续寻找它们所指挥的信号级联反应的组成部分。拟南芥根伸长区表皮质膜最近被证明含有P2K1下游的阳离子运输途径（通道传导），并可能有助于细胞外ATP （eATP）信号传导。在这里，膜片钳电生理学已经被用来描绘根伸长区表皮质膜对eATP有反应的两个进一步的电导，包括一个允许氯离子运输的电导。这一观点阐述了这些电导如何与之前在根中表征的电导进行比较，以及它们如何共同作用以实现eATP信号传导的早期事件，包括作为第二信使的细胞质无钙的升高。在定性模型中考虑了eATP激活NADPH氧化酶可能产生的活性氧（ROS）的作用，该模型还考虑了各种阳离子和阴离子电导的协同作用对质膜电位的调节。eATP信号传导通道的分子特性仍然是谜，但可能在谷氨酸受体样通道、环核苷酸门控通道、膜联蛋白和铝活化的苹果酸转运蛋白的多基因家族中发现。
Adenosine 5'-triphosphate (ATP) is an important extracellular signaling agent, operating in growth regulation, stomata! conductance, and wound response. With the first receptor for extracellular ATP now identified in plants (P2K1/DORN1) and a plasma membrane NADPH oxidase revealed as its target, the search continues for the components of the signaling cascades they command. The Arabidopsis root elongation zone epidermal plasma membrane has recently been shown to contain cation transport pathways (channel conductances) that operate downstream of P2K1 and could contribute to extracellular ATP (eATP) signaling. Here, patch clamp electrophysiology has been used to delineate two further conductances from the root elongation zone epidermal plasma membrane that respond to eATP, including one that would permit chloride transport. This perspective addresses how these conductances compare to those previously characterized in roots and how they might operate together to enable early events in eATP signaling, including elevation of cytosolic-free calcium as a second messenger. The role of the reactive oxygen species (ROS) that could arise from eATP's activation of NADPH oxidases is considered in a qualitative model that also considers the regulation of plasma membrane potential by the concerted action of the various cation and anion conductances. The molecular identities of the channel conductances in eATP signaling remain enigmatic but may yet be found in the multigene families of glutamate receptor-like channels, cyclic nucleotide-gated channels, annexins, and aluminum-activated malate transporters.