Nature Plants ( IF 18.0 ) Pub Date : 2020-10-05 , DOI: 10.1038/s41477-020-00773-1 Hiraku Suda , Hiroaki Mano , Masatsugu Toyota , Kenji Fukushima , Tetsuro Mimura , Izuo Tsutsui , Rainer Hedrich , Yosuke Tamada , Mitsuyasu Hasebe
The leaves of the carnivorous plant Venus flytrap, Dionaea muscipula (Dionaea) close rapidly to capture insect prey. The closure response usually requires two successive mechanical stimuli to sensory hairs on the leaf blade within approximately 30 s (refs. 1,2,3,4). An unknown biological system in Dionaea is thought to memorize the first stimulus and transduce the signal from the sensory hair to the leaf blade2. Here, we link signal memory to calcium dynamics using transgenic Dionaea expressing a Ca2+ sensor. Stimulation of a sensory hair caused an increase in cytosolic Ca2+ concentration ([Ca2+]cyt) starting in the sensory hair and spreading to the leaf blade. A second stimulus increased [Ca2+]cyt to an even higher level, meeting a threshold that is correlated to the leaf blade closure. Because [Ca2+]cyt gradually decreased after the first stimulus, the [Ca2+]cyt increase induced by the second stimulus was insufficient to meet the putative threshold for movement after about 30 s. The Ca2+ wave triggered by mechanical stimulation moved an order of magnitude faster than that induced by wounding in petioles of Arabidopsis thaliana5 and Dionaea. The capacity for rapid movement has evolved repeatedly in flowering plants. This study opens a path to investigate the role of Ca2+ in plant movement mechanisms and their evolution.
中文翻译:
转基因维纳斯捕蝇器中可视化陷阱关闭过程中的钙动力学
食肉植物维纳斯捕蝇草(Dionaea muscipula(Dionaea))的叶子迅速关闭以捕获昆虫的猎物。闭合响应通常需要在大约30 s内对叶片上的感官毛发进行两次连续的机械刺激(参考1,2,3,4)。人们认为Dionaea中一个未知的生物系统会记忆第一个刺激并将信号从感官毛发传导到叶片2。在这里,我们使用表达Ca 2+传感器的转基因Dionaea将信号记忆与钙动力学联系起来。刺激感官毛发导致胞质Ca 2+浓度([Ca 2+ ] cyt)从感觉毛开始,并蔓延至叶片。第二种刺激将[Ca 2+ ] cyt增加到甚至更高的水平,达到了与叶片闭合相关的阈值。由于第一次刺激后[Ca 2+ ] cyt逐渐降低,因此第二次刺激引起的[Ca 2+ ] cyt增加不足以满足大约30 s的假定运动阈值。机械刺激触发的Ca 2+波的移动速度比拟南芥5叶柄中的伤害引起的移动快一个数量级。和狄奥尼娅。快速移动的能力已在开花植物中反复发展。这项研究为研究Ca 2+在植物运动机制及其进化中的作用开辟了道路。