Light-Sensitive Self-Organization in Plant Cells

Photosynthesis in plants is one of the main players in the survival of whole ecosystems on earth. To guarantee the efficiency of this process, plants have to actively adapt to ever-changing light conditions. Besides the well-known phototropism (the growth of plants towards the light), plants can re-arrange the internal structure of cells by the active motion of chloroplasts on short timescales. These organelles are confined between the cell membrane and vacuole and can move inside the cytoplasm via actin-mediated mechanisms. Remarkably, the simple - yet elegant - interplay of light-sensing and active forces leads to various modes of collective motion. Here, we show that the chloroplasts can behave like a densely packed light-sensitive active matter sytstem, whose non-gaussian athermal fluctuations can lead to various self-organization scenarios. In this study, we aim to establish a new framework to investigate the dynamics of active biological systems featuring intriguing dynamical phase transitions.