From their experience, gardeners and farmers recognize that plants respond to temperature. In a warm winter, buds and flowers emerge early, while a cold summer brings less fruit.
But science never been able to determine how plants were able to measure the thermal variations.
What is striking is that this sensor was camouflaged in another sensor dedicated to measuring the ambient light (phytochrome) and was known since the 1950s.
One of the work’s main authors Argentines Jorge Casal and Martina Legris, researchers from CONICET and the Leloir Institute Foundation. The scientists were conducting a detailed study of the phytochrome, plant proteins responsible for measuring the light spectrum of far-red and red light.
“To our surprise, we discovered that phytochrome integrates this data at the same time light and temperature, takes stock of that information and communicates it to the plant to meet environmental conditions,” said Casal.
Philip Wigge, University of Cambridge, is the lead author of another work on the plant thermometer. Together with his team, determined that phytochrome night work exclusively as thermometers.
During the day, the phytochrome is activated by light. The protein is responsible for restricting the growth of the plant.But if you are in the shade, it is inactive in the absence of light, which allows faster growth with the aim of finding light.The change is given in seconds.
But overnight phytochrome is inactive due to lack of light, but gradually, known as dark reversal mechanism. Wigge group graduality determined that is directly proportional to the ambient temperature.
“The warm temperatures accelerate the dark reversal, so inactive phytochrome quickly come to the state, which accelerates the growth of plants,” explains Wigge.
Legris, the Argentine group, explains that the difference between his work and that of Wigge is that they proved that even when there is light phytochrome can sense the temperature. “The receptor studied is the same, but the mechanisms that occur during the day and at night are subtly different. The reversion reaction that occurs during the night is much slower than that which occurs during the day, “he explains.