Plant roots have their own "thermometer"

Researchers at the Martin Luther University of Halle-Wittenberg (MLU), in Germany, discovered that plant roots have an independent temperature sensing system. It allows the roots to adjust their growth according to soil conditions, functioning as a true underground "thermometer".

The research team, led by Professor Marcel Quint from MLU's Institute of Agricultural and Nutritional Sciences, carried out a series of experiments to investigate how different plants, including nightshade, cabbage and tomatoes, react to variations in temperature. The results, published in The EMBO Journal, challenge previous understanding that the plant stem controlled the growth process in response to temperature.

"Our study shows that roots have a surprising ability to respond independently to changes in temperature, even when the stem is removed," Quint said. "This suggests that roots are not mere passive receptors of signals from the stem, but have their own temperature sensing and response system."

The researchers also found that roots increase production of the growth hormone auxin in response to higher temperatures. This hormone is transported to the tips, where it stimulates cell division and allows the roots to reach deeper, cooler layers of soil.

"This makes sense from an evolutionary perspective, as heat and drought often occur together. Therefore, plants would benefit from seeking deeper, cooler soil layers that contain water," Quint explained.

The discovery has significant implications for plant breeding, especially in a context of climate change. "Understanding the molecular basis for temperature-dependent root growth can help us effectively equip plants against drought stress and achieve long-term stable yields," Quint said.

The study can be read at the link below: