Electrically Induced Bubble-Assisted Substance Delivery into Intact Plant Cells and Tissues

Substance injection into plant cells is typically performed using protoplasts, in which the cell wall has been removed. However, the process of removing the cell wall imposes significant stress on the cells, making injection into tissue-like structures difficult. Injecting substances into plants not only streamlines plant breeding but also enables the introduction of sensors for detecting plant hormone responses, thereby facilitating the understanding and control of plant physiological states. This study proposes a method for injecting molecules into plants without removing the cell wall by utilizing the cavitation effect of electrically induced bubbles. The proposed device consists of a metal wire positioned inside a glass tube. By varying the diameter of the metal wire, the electrical and mechanical stimulation applied to the target can be controlled. Using this method, successful gene delivery was confirmed by fluorescence observation and RT-PCR analysis in plant cells (Tobacco BY-2 cells, Nicotiana tabacum L. ) and plant tissue ( Arabidopsis thaliana , hereafter referred to as Arabidopsis) without removing the cell wall. Considering the limited efficiency of gene delivery into plants using conventional electroporation, these results suggest that combining mechanical stimulation with electrical stimulation is an effective approach for substance delivery. Furthermore, because the delivery conditions can be tuned by adjusting the electrical and mechanical parameters, the proposed method has the potential to be applied to a wide range of plant and animal tissues.