Plants do not wait hours to respond to intense sunlight—they react within minutes. Researchers at Bielefeld University and the Australian National University have discovered a new signaling pathway that enables plants to directly adjust their protein production before genes in the cell nucleus change their activity. The findings open new perspectives for climate-resilient crops.
Key facts at a glance:
Under high light, plants specifically regulate their protein production within ten minutes.
Short sequence elements in the messenger RNA act as molecular switches.
The mechanism could help make crops more resilient to climate stress.

Plants may appear unresponsive. Yet when their environment changes, they respond within seconds. Sudden exposure to intense light is particularly challenging. It can disrupt photosynthesis and damage cells. A study to be published in the journal Molecular Plant now shows how rapidly and precisely plants respond.
“We were able to demonstrate that plants reprogram their protein production within minutes—well before gene activity in the cell nucleus changes,” says first author Dr. Marten Moore. He began his research at Bielefeld University and later continued it at the Australian National University in Canberra. “This means we have identified an additional, very rapid regulatory layer.”
Direct regulation instead of detouring via genes
Until now, research largely assumed that chloroplasts—the sites of photosynthesis in plant cells—send signals to the nucleus. There, genes are activated to initiate protective programs. This process takes time because new messenger molecules first have to be produced.
The research team from Bielefeld and Canberra now shows that plants can react faster. They directly intervene in protein synthesis. Proteins are the working molecules of the cell; they are produced when ribosomes “read” the blueprint of messenger RNA (mRNA) and translate it into proteins. Under high light, plants reprogram this step.
Within ten minutes, the pattern of which mRNAs are most actively translated into proteins shifts. In particular, more proteins essential for photosynthesis in the chloroplast are produced. In this way, the plant protects itself against damage caused by excess light—known as photoinhibition, a light-induced impairment of the photosystem.
Small RNA sequence elements with major impact
This rapid reprogramming is triggered by short sequence elements at the beginning of the mRNA. These sequences serve as docking sites for an enzyme called GAPDH, which normally plays a role in sugar metabolism. Depending on light intensity, this enzyme binds to or dissociates from the mRNA. In doing so, it acts like a switch that turns protein production up or down.
The researchers demonstrated the mechanism not only in the model plant Arabidopsis, but also in the millet species Setaria viridis. This suggests that it is widespread across many plant species.
The study is the result of a long-standing collaboration. The underlying hypothesis was developed around 18 years ago by the research group led by Prof. Dr. Karl-Josef Dietz at Bielefeld University. The project was funded, among others, by the German Research Foundation (DFG) and the Australian Research Council.
In the face of increasing weather extremes, the discovery gains additional significance. Plants are increasingly exposed to intense sunlight, heat and drought. Understanding how they adapt within minutes may, in the long term, enable the development of crop varieties that deliver more stable yields—without fundamentally altering their genetic makeup, but by specifically harnessing natural regulatory elements.

Assessment by Prof. Dr. Karl-Josef Dietz
“Our findings show for the first time that chloroplasts can directly and extremely rapidly influence protein synthesis in the cytoplasm. This fundamentally expands our understanding of plant stress responses. Particularly interesting is the discovery that short RNA segments in conjunction with specific regulator proteins function as switches. This insight opens up concrete perspectives for breeding more robust crops—a highly relevant issue in the context of climate change.”