Researchers at the University of Bayreuth and Heinrich Heine University Düsseldorf have uncovered a previously unknown mechanism in the perception of light and heat by plants. This discovery could lead to advancements in optogenetics, biotechnology, and our understanding of plant adaptation to environmental changes, including the impact of climate change.
Revealing Phytochromes’ Dual Role
How plants perceive and respond to the world around them is a central question in biology, and light together with temperature are likely two of the most critical environmental factors that plants need to sense. The process of light mediated crowd avoidance is importantly controlled by the photoreceptor protein class, Phytochromes. These pigments are capable of transmutation in reaction to various wavelengths of light and temperature variations; inducing different responses –rage – secretion, growth and other similar physiological changes.
The researchers discovered that it was the fruits’ interaction with phytochrome B and other proteins called phytochrome-interacting factors (PIFs) that allowed the plants to sense temperature. They found that dissolution of these complexes is accelerated greatly as temperature rises from 15°C to 30°C and formation remains almost constant in this range. These results indicate that plants are able to sense temperature changes and induce responses at a physiological level through an unknown molecular mechanism.
A surprising find: bidirectional conversion
The authors then discovered another, rather surprising, phenomenon that formed the core of their study: while investigating this question proprio motu the researchers found out that complexes formed between phytochrome B and PIF proteins decreased as light intensity grew more and not increased as one might expect. This is a result of red-light-induced rapid bidirectional conversion of phytochrome B from the inactive Pr state to the active Pfr and back again.
The result shows that a family of plant phytochromes transduces different red light intensities and temperatures into physiological responses using an additional, uncharacterized molecular pathway. The findings have direct applications for agriculture and could be widely applicable across other fields, from biotechnology to light-control over gene activity using optogenetics.
Biotechnology and Implications for Climate Change Adaptation
This research provides new tactics for using plant phytochromes in bioengineering, with applications that include the pinpointed activation of genes and the production of specific proteins. Another exciting part of this new discovery is how it can influence our view on light and temperature signaling in plants, for studying effects of climate change on plant growth and survival.
As the decrease in plants adapting to the environment now continues indeed could be a condition that makes it even worse when gradually warming the global climate. Understanding the molecules behind light and heat sensing in plants brings scientists closer to developing climate-resilient crop variants as well as optimizing future agriculture methods, essential for global food security.
