Plant “Muscles” Show Proprioception
The sense of position in space was
thought to be unique to animals.
Trees exhibit proprioception, too.
We take it for granted that most trees in a forest grow vertically. Scientists thought that growth hormones that respond to light and gravity cause this pattern. But what happens when a young tree is curved out of shape by some force? Why doesn’t it continue at an angle? Perhaps you have seen bent trees that somehow “corrected” their orientation. Scientists in France have figured out how they do it. Trees have a kind of “muscle” called tension wood that sets them back onto a straight-up path.
A newly discovered role for tension wood: the “muscle” trees use to correct their posture (National Research Institute for Agriculture, Food and Environment [INRAE], 2 Sept 2026). Through controlled experiments, scientists found that trees have a sense of their position in space.
A research team from INRAE and the University Clermont Auvergne has shown that trees are capable of correcting a curvature they detect in their stems through a specific biological process. In the study, young trees with bent stems were placed in an experimental set-up that prevented them from sensing their orientation relative to light and gravity. The only sense remaining to the trees was the perception of their own curvature. Under these conditions, the scientists observed the formation of a particular type of wood, known as tension wood, which acts like a muscle to correct the curvature of the stem, allowing it to realign within a few weeks. Published in New Phytologist, the findings show how plants—under natural conditions—finely perceive their own shape and combine this information with signals relating to their orientation to adjust their posture.
The new findings build on work from 2012 at INRAE that detected a proprioceptive sense in plants. This sense, the ability to detect position of on organism’s body parts in 3-D space, was “long believed to be specific to animals.” A young tree growing on a mountain slope, for instance, will grow tension wood on its upper side to cause it to curve up to a vertical position. Until the current work, the biological mechanism was unknown.
It took about 10 days for young poplar trees in an experimental setup deprived of information about light and position to fix their orientation. They responded to their sense of their own orientation by growing tension wood in just the right position, correcting their growth pattern.
The formation of tension wood on the upper side, which had caused the stem to bend upwards, ceased when the device was activated, while a wood identical in every respect formed on the opposite side. The latter appears to function as an antagonistic muscle, generating a pulling force in the opposite direction and progressively restoring the stem to a straight form.
Simple, isn’t it? Problem solved by scientific experiment? Not exactly; like everything else in biology,
Tension wood formation is a complex biological process that is regulated at the cellular level and unfolds through several successive stages. The process is also governed by the plant’s proprioception.
Bent trees can correct their orientation using antagonistic “muscles.” (DFC)
The use of antagonistic forces sounds akin to animal muscles that grow in pairs, like biceps and triceps, to counteract one another and maintain balanced movement. Plants, too, have a “genuine sensorimotor loop” that takes advantage of its proprioceptive sense and grows the appropriate amount of tension wood in the right place to achieve balanced vertical growth. It takes fine tuning to achieve this:
These results show that plants combine fine perceptions of their environment (such as light and gravity) with an awareness of their own shape. They integrate and process this information to activate tension wood in different directions, thereby achieving or maintaining the most appropriate posture. These key abilities contribute to the resilience of trees when faced with extreme events that can alter their position, such as storms or landslides, a trait of particular importance in the context of climate change.
Other than that brief nod to political correctness, this Darwin-free press release opened up windows into additional complex processes at work that are too easily taken for granted.
Other Botanical News
No Smartphone, No Problem: Plants Have Their Own Built-In Season-Meter (University of Tsukuba, 21 Aug 2026). Here’s another skill in plants that requires cooperating parts. Researchers in Japan found that three genes for timing cooperate as a “Season-Meter” that allows them to accurately predict what time of year is approaching.
You check your phone before deciding what to wear tomorrow. Plants do something similar: they carry an internal gadget called a Season-Meter that tracks temperatures over the preceding weeks or months to help determine when to flower. By comparing two wild perennial plant species over two years, the researchers found that each of the three genes in this Season-Meter operates over a different timescale, ranging from days to nearly five months, and that together they reliably forecast all four seasons of the year.
The press release says that the Season-Meter works epigenetically instead of in the DNA. It requires an internal memory and a capacity to predict the weather in advance. That’s something even humans struggle with.
Such preparation requires an internal memory. Since DNA itself cannot record a changing environment, plants instead preserve information about past temperatures through epigenetic changes in chromatin.
How did this remarkable skill come to be? Unfortunately, the science writer fell back into the just-so storytelling habit: “evolution has favored systems that allow plants to prepare in advance,” the writer says, personifying evolution. The paper in PLoS One, however, only makes one subtle passing reference to evolution that doesn’t affect the evidence of functional design in the observations.
When something works, it doesn’t follow that it evolved. Paul Nelson’s father used to say, “If something works, it’s not happening by accident.” Evolutionists sometimes say that design is a science stopper. On the contrary, knowing that something is not an accident is a strong motive to figure out how it works. The real science stopper is appealing to the Stuff Happens Law.
Here were two examples of processes in plants that surround us that work because of complex systems already in place. These systems require sensors, responders, and libraries of information on how to solve problems. They all had to be in place, working together, before the seed sprouted or the species came to be. Those are hallmarks of intelligent design and engineering. Let us never take them for granted again.