Trees have muscle-like wood that pulls them upright

Trees have muscle-like wood that works in opposing directions to pull themselves upright, researchers at INRAE reported this week. To isolate the sense, they placed young poplars on a rotating platform inside a sphere lit evenly from every angle, removing any cue from gravity or sunlight. The trees, starting from a curved position, slowly straightened anyway. The team found that tension wood, long thought to form only on a stem's upper side, had begun developing on the opposite side instead, producing a counter-pull that worked like an opposing muscle group. Trees were sensing their own shape and correcting it, a quality called proprioception once believed to belong only to animals. The work could help breed straighter crops and reduce lodging, when grain collapses before harvest. Bruno Moulia, INRAE research director, described a "genuine sensorimotor loop operating in the woody parts of trees," and said the goal is trees that stay relaxed, whatever life throws at them.