The Question
Plants thrive in constantly changing environments, but unlike animals, they cannot move to find food or escape unfavorable conditions. Instead, they rely on highly efficient cellular stress responses and, most importantly, the ability to adjust their growth to reach favorable areas while avoiding unfavorable ones. This precise directional growth is particularly pronounced in roots, which explore the soil to locate water and nutrients, optimizing their uptake from the most favorable soil patches. These capacities depend on the ability to perceive the local environment and make growth decisions. However, beyond responding to basic cues like light and gravity (which have been documented and explored), can plants sense their environment in a way that resembles how animals use smell and taste — abilities that help animals locate resources and avoid dangers?
Surprisingly, this question can’t yet be answered as very little is known about how plant roots detect and respond to the vast array of chemical cues in the soil that carry information about the local environment. However, plant genomes encode hundreds to thousands of receptor kinases — a class of proteins known for recognizing chemical signals and triggering cellular responses. Yet, the function of nearly all these receptors remains a mystery. The Mapping the Root Perceptome project hypothesizes that, much like animals, plants use these receptors to detect a wide range of yet unidentified chemical cues, guiding their growth decisions in response to their environment.
“My research could transform how we think about plant life, opening new paths for sustainable agriculture, improving ecosystem resilience, and advancing climate change solutions. By comprehensively decoding how plants sense their environment, we will better understand their enormous success on our planet and can better harness their potential to support life on Earth.”
— Wolfgang Busch
The Approach
The Mapping the Root Perceptome project aims to map the chemical world that roots can perceive — that is, their “perceptome” — and investigate whether roots function as sensory organs with specialized structures for detecting and interpreting chemical information, similar to how tongues and noses perceive and process signals in higher animals. By systematically testing how thousands of chemicals influence root growth and identifying the root structures and receptors involved in perception, the researchers hope to uncover the molecular and cellular mechanisms by which roots sense and respond to external cues.
Discoveries resulting from this work will significantly advance our understanding of how neuronless organisms like plants perceive and interact with their surroundings. This knowledge could have practical applications in agriculture and environmental sustainability, helping to develop plants with enhanced resilience to changing conditions, improved nutrient uptake, increased carbon storage in the soil, and even engineered root systems tailored for specific environments. Just as breakthroughs in human and animal sensory biology have revolutionized medicine and technology, this research will reshape how we think about plant life — revealing the hidden sensory sophistication of roots and their capacity to navigate and adapt to their environment.
The Mapping the Root Perceptome project is being led by Wolfgang Busch at the Salk Institute for Biological Studies in La Jolla, US.
Feature image: Laser confocal microscopy image (maximum intensity projection) of an Arabidopsis thaliana root tip. Cell walls are visualized in yellow/purple and nuclei appear as bright yellow spots. (Photo: Salk Institute)
