They discover how plants know where light comes from

a New study Who combined knowledge of biology and engineering to try to discover how plants know where light comes from discovered that A Plant tissues sensitive to light Use the Optical properties of the air-water interface To generate a light gradient that is “visible” to the plant, according to what its authors publish in the journal Sciences.

more than living creatures (microorganisms, plants and animals). Ability to determine the origin of the light source, Even in the absence of a visual organ similar to the eye. This information is invaluable to Guidance Or position yourself optimally in your environment.

Visualize where the light comes from It is especially important for plants that use this Information for your member status, a phenomenon known as phototropism. This allows them to capture A greater amount of solar radiation, Which it then converts into chemical energy through photosynthesis, a vital process necessary for the production of almost all the food we consume.

Although the photoreceptor that initiates phototropism has been known for some time, Optical properties of light-sensitive plant tissues They have until now been a mystery.

a Interdisciplinary study Which brings together the knowledge of the teams of Dr. Christian Fankhauser, Professor and Director of the Center for Integrative Genomics at the Faculty of Biology and Medicine at the University of University of Lausanne; Dr. Andreas Schuler, head of the Solar Energy Conversion Nanotechnology Group at the Laboratory for Solar Energy and Building Physics at the École Polytechnique Fédérale de Lausanne (Switzerland) and the Center for Electron Microscopy at UNIL, discovered An amazing property of fabrics This allows plants to detect directional light signals.

“It all started with Observation of a mutant of the model type “Arabidopsis thaliana”, “His torso was surprisingly transparent,” explains Christian Fankhauser, who led the research.

These plants did not respond properly to light. The biologist then decided to turn to the knowledge of his colleague Andreas Schuller, from EPFL, to continue the comparison between organisms. Specific optical properties of mutant versus wild-type samples.

“We discovered that the natural milky appearance of the stems of young wild plants was actually due to… The presence of air in the local intercellular channels Accurately on different fabrics. In mutant samples, the air is replaced by a watery liquid, Which gives them a transparent appearance,” continues the researcher.

They discovered that these Air-filled ducts They allow the light-sensitive stem to create a light gradient that the plant can “read.” And so can the plant Determine the origin of the light source. This phenomenon is due to the difference in optical properties of air and water, which make up the majority of living tissue.

“More specifically, Air and water have different refractive indices. This causes light to scatter as it passes through the seedling. “We have all noticed this phenomenon when admiring a rainbow,” explains Martina Legris, a postdoctoral fellow in Professor Fankhauser’s group and co-author of the study.

Thanks to their research, scientists revealed New mechanism Which allows organisms to perceive the source of light, allowing them to position their organs, such as leaves, so that they are… Improve light collection for photosynthesis.

As the study allowed Better understanding the formation of channels between air-filled cells, Which has different functions in plants, in addition to forming light gradients. Other uses include these channels Promote gas exchange And also allow Resistance to hypoxia (Low amount of oxygen) in case of floods. Its development, from the embryonic stage to adulthood, is still little known.

the Genetic resources used in this study will be useful for To better understand the formation and maintenance of these interesting structures, The researchers conclude.