A recent study has shown that when the morning light breaks, plants are among the first organisms to “wake up.”
Published in the journal Molecular Plant, this research examined the activity of various genes in plants during the early morning hours. Researchers discovered that at the moment the sun rises on the horizon, plants are already prepared and waiting to start their day.
This regular schedule helps plants take advantage of optimal conditions to harness energy from sunlight, as well as create opportunities for pollinators to be most active.
At sunrise, plants are ready and waiting to begin their day.
Maximizing efficiency is a significant challenge for crops. Depending on the growing area and specific locations within that area, sunlight and water may be insufficient. Meanwhile, plants cannot move to seek out what they need, so they must utilize everything that nature provides.
To gain a better understanding of how plants respond when the sun begins to rise over the horizon, researchers from several universities collaborated to conduct an intriguing experiment. They sampled a flowering plant, watercress, every two minutes after sunrise. With these samples, the research team was able to identify the waves of activity occurring within the plants as the morning light brightened.
“We began to describe in greater detail the dynamic characteristics at dawn, focusing on the expression of transcription factor genes. We found three distinct waves of gene expression within two hours after dawn. Many of these genes are known to be sensitive to light and temperature, but we wanted to specifically understand how the transcription of these genes is coordinated.
Interfering with signals from light receptors, circadian clocks, and light signals originating from chloroplasts caused issues in the expression of some genes, but a large proportion of genes remained unaffected. This shows us that some upstream pathways are redundant and additional regulatory organs are at work,” said Dr. Martin Balcerowicz, the lead author of the paper.
In simple terms, plants can respond to each new day just like animals. We have a natural circadian rhythm that always regulates us, ensuring that we wake up in the morning and feel tired at night, but we are also influenced by sunlight, which stimulates us in different ways.
Plants seem to have adopted this dual approach with backup systems to ensure they “wake up,” whether due to routine or the presence of bright light.
“An important feature we observe in gene expression is the result of the onset of light, which is very useful in helping us understand how plants respond to light and, particularly, how the prolonged effects of dawn light influence growth for crops under artificial light,” added Dr. Daphne Ezer, a senior author of the study.
