Antagonism between blue- and red-light signaling controls thallus flatness in Marchantia polymorpha.
Roetzer J, Asper B, Meir Z, Edelbacher N, Mérai Z
Plant Signaling
Every time your houseplants lean or droop toward a window, the same tug-of-war between red and blue light wavelengths is happening — this research reveals the molecular switch that keeps plants growing level when light is balanced.
Liverworts are ancient, simple plants that grow as flat, ribbon-like sheets along the ground. Researchers found that red light tells the liverwort to curl downward while blue light tells it to curl upward — like two hands pulling in opposite directions. In normal white sunlight, which contains both colors, the two signals balance perfectly and the plant stays flat.
Key Findings
Red-light signaling causes downward curling (epinasty) and blue-light signaling causes upward curling (hyponasty); together in white light they balance to produce flat growth.
Plants with a disabled blue-light receptor curled down; plants with a disabled red-light receptor curled up — confirming each receptor drives the opposing response.
Two BBX transcription factor genes act antagonistically downstream of light: losing both BBX1 and BBX5 together restored flat growth, proving they are key mediators of this light-balancing system.
chevron_right Technical Summary
Scientists discovered that red light and blue light give opposite growth instructions to liverworts, pulling the plant body in competing directions. When both colors are present — as in natural sunlight — the signals cancel out, producing a perfectly flat plant.
Abstract Preview
The growth orientation of the Marchantia polymorpha thallus-a system of dorsiventralized, indeterminate axes-is modulated by light. We show that red and blue light act antagonistically to control t...
open_in_new Read full abstractAbstract copyright held by the original publisher.
Species Mentioned
Was this useful?
Nanoplastics interfere with plant-mycorrhizal communication and limit plant growth.
Microplastics breaking down in your garden soil are quietly strangling the beneficial fungi that help your vegetables absorb phosphorus and other nutrients, ...