Analysis of plant cells’ response to gravity could help designs inspired by nature

From wind turbines and buildings to robots and bionic cars, the use of innovative methods and new technologies is increasingly inspired by nature. As they mimic biological systems, the applications of such solutions are known as biomimetics or biomimicry. These are set to grow, thanks to research that helps us understand how living organisms adapt to changes in external factors.

A study on gravity perception in plants, partially supported by the EU-funded PLANTMOVE project, lays the foundation for bio-inspired industrial applications. The findings were recently published in the journal ‘Proceedings of the National Academy of Sciences’.

As noted in the article, if a plant is tilted it will alter its growth to bend back upwards. In order to detect the inclination, it uses cellular clinometers: cells filled with microscopic grains of starch called statoliths. Researchers from the French National Center for Scientific Research (CNRS), the French National Institute for Agronomic Research and Université Clermont Auvergne who conducted the study examined how these ‘gravisensors’ respond to even the tiniest deviation from the vertical.

They showed that despite their granular nature, statoliths move and respond to the weakest angle, as a liquid clinometer would do. The researchers said: “Comparison between the biological and biomimetic systems reveals that this liquid-like behaviour comes from the cell activity, which agitates statoliths with an apparent temperature one order of magnitude larger than actual temperature.” They added that the results “shed light on the key role of active fluctuations of statoliths for explaining the remarkable sensitivity of plants to inclination.”

Bio-inspired industrial applications

According to a press release by CNRS explaining the study, the team’s findings could help the development of “robust, miniature clinometers offering an alternative to today’s gyroscopes and accelerometers.” Clinometers are used to measure elevation angles above the horizontal, while gyroscopes are used to detect the deviation of an object from its desired orientation. The latter harnesses the principle of conservation of angular momentum, whereas accelerometers measure the rate at which the velocity of an object is changing. Applications for such sensors include smartphones, inertial navigational systems of aircraft and missiles, flight stabilisation systems of drones and collision prevention systems in vehicles.

As the project website states, PLANTMOVE, which is at the crossroad of plant mechanics and soft matter physics, addresses basic mechanisms used by plants to perceive mechanical stimuli and generate motion. “How to transport fluids, move solids or perceive mechanical signals without the equivalent of pumps, muscles or nerves? This challenge, which is relevant to microfluidics and robotics, has long been solved by plants.”

The ongoing PLANTMOVE (Plant movements and mechano-perception: from biophysics to biomimetics) project uses a multidisciplinary and multi-scale approach to improve the understanding of basic plant functions. As indicated on the CORDIS project web page, such an approach “offers new strategies to design smart soft materials and fluids inspired by plant sensors and motility mechanism.”

Understanding how these organisms adapt to external stress and forage for food, water and light is crucial in agronomy and plant science for better managing plant resources. The same web page adds that PLANTMOVE offers a promising path for biomimetic designs in engineering and technologies.

For more information, please see:
PLANTMOVE project website