Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Wuerzburg University, Julius-von-Sachs-Platz 2, 97070 Wuerzburg, Germany.
Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Wuerzburg University, Julius-von-Sachs-Platz 2, 97070 Wuerzburg, Germany.
Curr Biol. 2022 Oct 10;32(19):4255-4263.e5. doi: 10.1016/j.cub.2022.08.051. Epub 2022 Sep 9.
Since the 19 century, it has been known that the carnivorous Venus flytrap is electrically excitable. Nevertheless, the mechanism and the molecular entities of the flytrap action potential (AP) remain unknown. When entering the electrically excitable stage, the trap expressed a characteristic inventory of ion transporters, among which the increase in glutamate receptor GLR3.6 RNA was most pronounced. Trigger hair stimulation or glutamate application evoked an AP and a cytoplasmic Ca transient that both propagated at the same speed from the site of induction along the entire trap lobe surface. A priming Ca moiety entering the cytoplasm in the context of the AP was further potentiated by an organelle-localized calcium-induced calcium release (CICR)-like system prolonging the Ca signal. While the Ca transient persisted, SKOR K channels and AHA H-ATPases repolarized the AP already. By counting the number of APs and long-lasting Ca transients, the trap directs the different steps in the carnivorous plant's hunting cycle. VIDEO ABSTRACT.
自 19 世纪以来，人们就知道食虫的维纳斯捕蝇草具有电兴奋性。然而，捕蝇草动作电位（AP）的机制和分子实体仍然未知。当进入电兴奋阶段时，陷阱表达了一组特征性的离子转运体，其中谷氨酸受体 GLR3.6 RNA 的增加最为明显。触发毛刺激或谷氨酸应用会引发 AP 和细胞质 Ca 瞬变，两者都以相同的速度从诱导部位沿着整个陷阱叶表面传播。在 AP 过程中进入细胞质的初始 Ca 部分被定位于细胞器的钙诱导钙释放（CICR）样系统进一步增强，从而延长了 Ca 信号。当 Ca 瞬变持续时，SKOR K 通道和 AHA H-ATPases 已经使 AP 复极化。通过计算 AP 和持久的 Ca 瞬变的数量，陷阱指导食虫植物的捕食周期的不同步骤。视频摘要。
